Tor Giffard 2 1951-71 in P4 - North Devon/Cornwall LSWR (former routes)

[Torr Giffard LSWR 1951-71]

Hi Alan,

 

I've tested the sound properties using both single and double layers of cork...see earlier in the thread...and found little difference. The main silencer was the combination of T section stretchers at 1ft intervals, 2mm aluminium sheet decking and gutter sealant applied to each underside aluminium joint in contact with the deck...see earlier clips. I'll be testing the acoustic qualities again once the bridge decks are complete...the linking frame between the bridges at the twin fiddle yard end is in place, the levelling sledge has been used across all four frames and track is starting to be laid in earnest.

 

A rake of four loaded ex ironstone hoppers (2 axle) were trundled along the track atop the 'station to bridges' frame several times this morning (as per your suggestion) and apart from a satisfyingly solid wheel to rail sound there was nothing else audible at all, regardless of speed. Bear in mind that the cork isn't even levelled yet or the track bonded to it. 

 

Similarly, D1037 Western Empress was trialled with the same rake and the only audible sound was the loco drive mechanism...no layout generated noise (resonance/vibration/hollow tin can sound etc) whatsoever.

 

 

Ongoing progress

 

Another fulcrum on which the shape/design of this layout turns is 'at large'. The original design for the layout included 'barn door' style opening sides to allow 'access all areas' in the event of a derailment etc. This has bothered me ever since I conceived of the idea because trying to open large side access doors in a crowded exhibition hall/making scenic detail vulnerable to passing elbows, rucksacks etc is an unnecessary risk. Instead, I've identified 4 key locations (adj. the double jnc; mid station area on the River Torridge side, mid station area on the yard side and adj. the Exeter end of the station where 2ft x 2ft x hypoteneuse triangles of 'drop and wheel to one side' areas of non-track, scenic detail can be located in order that I can move beneath the layout and access any given track location on the scenic section. Similarly, a section of the wooded hillside between the bridges at the twin fiddle yard end will be able to be wheeled back to allow access to that end of the twin bridges.  Yes there is more metal cutting/shaping to do but the layout can then remain intact and less vulnerable when access is required to problem areas.

 

Sound system wise...now is the time to identify speaker locations for such as the deep rumble of either long or short trains crossing one or both of the bridges, cascading water in the East Okement river channel; locos accelerating away from token exchange or station stop positions etc. More random/less specific speaker positions will cater for birdsong etc.            

 

Dave   

[islandbridgejct]

Hi Dave,

 

Glad to hear it's good so far. The bonding of track to cork and cork to board might be the thing to watch out for. At the moment the track is floating so the vibration is not transferred to the board. I remember a particularly disastrous experiment back when I was 16 or so. I put down track directly to chipboard and ballasted with granite chips held in place with powdered resin glue soaked in water. When it dried it was harder than concrete and the noise in the sitting room underneath was so bad that I couldn't run trains when anyone was in there. What I've done with my present boards is to fix the lower layer of foam at about 6 points, and leave it free to float otherwise. The upper layer of cork is glued to that with wood glue, and I'm experimenting with Copydex and acrylic medium to fix the Carr's ballast in place. (But I can't say if any of this works yet.)

 

Your removeable scenery sounds quite complex, but with such wide boards you'll need something of the sort.

 

I'm a bit wary of sound systems. From what I've heard of them, if they're on board, you get the sound of the engine all the time rather than the sound of the approach, the engine passing, and then the rolling stock on the rail joints. It doesn't sound like it does when I'm there. I think placing speakers at bridges and the like could give rise to a similar problem: do you manage the sound to represent a train approaching the station or going away, or do you produce it for someone moving alongside the train at the same speed? It's not just the doppler effect. You experience the sound differently if you're at lineside, 100 feet away, or 500 feet away.

 

I'll look forward to reading what you decide.

 

Alan

[Torr Giffard LSWR 1951-71]

Alan,

 

I hear that the American's are in the lead with layout based sound....I'll be looking at a few of their ideas before I jump. One area of thought at the moment is to have several Ipod style players...each with their own speakers and sound categories playing around the scenic section simultaneously at low volume, to produce a more complex sound experience. This is after all a 'train in the landscape' layout and viewers will be observing trains from 5-6ft distance. At that range all manner of other sounds can come into play and the actual train noise can be somewhat distant.

 

Ongoing progress   

 

A second un-rebuilt Bulleid West Country is now on order....34042 Dorchester with original raved tender...identity yet to be decided but will be compatible with a mid 50s carmine & cream coach rake. Disc headcode fitted 22 imminent.

 

The first disc headcode class 22 arrived today. This will become D6306 in all over green 1961 livery to be paired with Bulleid 3 coach set 857 (BSKs 2515 & 2516 and CK 5915) for Exeter - Plymouth - Exeter services. 3 Comet coach kits (2 x S4 & 1 x S6) ordered. 

 

Hornby WC 34042 Dorchester duly collected from 'The Crystal Garden', Solva. Preferred option for this one is as an early recipient of the dark green livery running with a mainly carmine & cream coach rake as an early fifties ACE. Many reference pictures and much text to check for prototypical identities and year. 34036 Westward Ho! is looking likely after checking: smoke deflectors, tender, AWS equipment etc 

 

Rumney models & David Geen asked to provide the 8 x 6 wheel milk tank kits req. to model the two milk train rakes for TG. 

 

The 2m long 4mm dia stainless rods were waiting for me on arrival back home...bridging practice to follow. 

 

Three of the new Hornby Maunsell SO coaches are the latest stock arrival. 

 

An old schoolmate is dropping by on Monday to check progress.with the layout....we happened to be walking together past the long closed Cheadle (Staffs) station (branch off the Stoke to Derby line) in the mid 70s when we both witnessed a class 50 arriving with empty sand/gravel opens....an astonishing sight for the line and traffic involved.   

 

Current progress includes checking out machine screws suitable for securing the 4mm dia. stainless rod to the 2mm aluminium bridge deck. 2mm screws require too big a hole to be drilled in the rod, therefore, I'm awaiting delivery of 10 BA brass nuts & bolts from  http://www.ba-bolts.co.uk/brasscsk.html

 

Positioning the station - bridges frame and Plymouth bridge frame ready to receive the Barnstaple bridge frame and bridges linking frame at the fiddle yards end has meant a further reorganisation of the workroom, with the plate glass reference surface now re-housed in the shed. The sketch map shown on page one of this thread is being upgraded to a scale map on the workroom wall to allow all individual frames to be indicated and for more details to be added. Some slewing of scenic detail is being undertaken so as to avoid awkward situations on corners/sides of frames. The River Torridge looks good as a 2ft width (in P4) waterway in a channel width of 3ft. This allows for a mud build up on the inside of the river bend beneath the bridges and will probably suggest the river as tidal at this point. A low stone block retaining wall will need replicating on the outside of the river bend, probably to be modelled on both sides, due to the curvature of the waterway at this point and likely erosion of bare soil banks on any prototype. 

 

Latest parcel from Eileen's includes more brass sheet from which the bowstring section side arches will be sliced and 4 x .5m lengths of brass L section suitable for mounting them to the aluminium bridge deck.

 

This mornings work includes cutting frame members for the transversely mounted 'bridges - twin fiddle yard' frame, mounting the frame end plates for the two bridge frames along the side of one longitudinal and fettling the locating dowels on same. This frame will have a 2ft x 2ft empty space between its longitudinals amidships as this will serve as the access point for the twin bridges.

 

Parts for the Barnstaple line curving girder bridge now ordered. This bridge will have twice as many (slightly smaller diameter) caissons as the Plymouth line bridge. There will be some alignment with those of the Plymouth bridge to aid river navigation. The main advantage of constructing these 4 frames together, besides their collective appearance, is to get the track spacings just right at the twin fiddle yards end of the bridges for running towards the linked traverser.  

 

Camera away for repairs at the moment.

 

Copy of Mike King's illustrated tome on Southern Coaches discovered, paid for and currently en-route to the TG reference library. 

 

Dave

[Torr Giffard LSWR 1951-71]

Evenin' all,

 

Current progress on TG involves clamping the Plymouth route bridge deck flat and level whilst drilling the 4mm dia. stainless steel rods and attaching them. One of the T section sky legs in the workroom was in just the right place for this. The first 2m longitudinal rod has been attached 10mm in from the curving edge of the deck using 2mm stainless, countersunk machine screws and flat nuts. A good supply of new 1.5 and 2mm twist drills is being maintained as the stainless rod isn't the easiest material to drill and rapidly blunts them. A file mark gives a reasonable start for the drill bit...the deck is firmly clamped to the rod adj. the drilling point with Mole grips. Very quickly, the deck is taking on a rigidity that bodes well for a solid bridge deck without the arched sides needing to be added before the levelling sledge is used across the cork trackbases. A 2nd rod will be added 10mm inboard of the opposite deck edge, followed by 2 equi-spaced additional rods in between. More 2m lengths of stainless rod are imminent for the Barnstaple line bridge.

 

The frame side plate for the transverse 'bridges to twin fiddle yards frame' has been fitted/the design of the remainder of the frame is underway and the bridge deck supports have been fabricated ready for the rigid bridge deck to be test-fitted. Once I'm happy with the deck position then the river bed will be modelled and the first polycarbonate panel fitted/clamped in place.    

 

The Mike King tome 'An Illustrated History of Southern Coaches' arrived today and is a worthy addition to the tally of reference books assisting with the development of the layout.     

 

 

Dave

[2ManySpams]

Copy of Mike King's illustrated tome on Southern Coaches discovered, paid for and currently en-route to the TG reference library. 

 

Dave

 

Cracking book Dave, especially when read in conjunction with the Gould books on Maunsell and Bulleid coaches. 

 

I've got a load of the data from the books transferred into a spreadsheet if that's any use to you. 

[Torr Giffard LSWR 1951-71]

...yes please Chris...I've got all 3 of the books which you mention and am busy trying to get to grips with the large amount of detail within them.

 

Best regards

 

Dave

 

Ongoing progress

 

The 2m 4mm dia. stainless rod for the Barnstaple line viaduct arrived today.

 

More rod drilled and screwed to the Plymouth bridge deck.  

 

The lovely weather this summer has seen plenty of opportunity to relax with a real ale and a pile of research material at the bottom of the garden. Amongst the variety of traffic planned for the Plymouth route on TG will be a couple of services diverted from the WR main line...not a rare event, esp. during heavy storms/flooding or maintenance along the Dawlish sea wall. Freight is the more likely traffic for these because the opportunities with a mixed rake are so diverse and I'm relishing the opportunity to include a few scratchbuilt Associated Octel chemical tanks, serving the plant at Hayle. Particular favourites include: a Grazebrook bromine tank, ditto by Charles Roberts. a couple of demountable bromine tanks on lowfit/conflat wagons, two types of small Chlorine tanks and a French built Ethylene Dibromide tank.

 

Latest arrivals are the 3 Comet coach kits for Bulleid set 857... and 2 of the Wild Swan Gordon Gravett tomes. Wheelests for the Comet kits ordered from Ultrascale.

 

Another day spent drilling 2mm holes at regular intervals along the bridge deck/stainless rod assembly. The routine is to first call in town for a load of standard 1.5 & 2.0mm drill-bits as broken and blunt ones are commonplace when drilling stainless. A centre-punched and partially or fully drilled 1.5mm hole acts as a good pilot for the 2mm bit.

 

The 4 x 2m rods are now securely bolted to the bridge deck and the result is rigid and flat.

 

The next step is to secure and level the deck in place across the caissons and abutments. 'L' section aluminium is being used to anchor the bridge deck square and at the correct height relative to the frame deck as part of the masonry arch abutments at each end of the viaduct. Each of the four intermediate anchor points atop of each of the four caissons will have height adjusters built in to allow the deck to be aligned absolutely flatly relative to the masonry arches. 

 

An enjoyable day with Andy Carlson (of St Ruth 2mm), David Ratcliffe and Trevor Mann today saw much discussion about Associated Octel traffic to Hayle and wagon types utilised. Another similar day is already on the calendar. 

 

Complaints from higher management re the conservatory looking untidy whilst either of the current modelling benches are in use have led to a third incarnation. This time a 26 inch square of worktop faced MDF has been hinged to the brick wall on the house side of the conservatory in such a way that no furniture is moved whilst it is in use and once finished with it can be allowed to hang flat to the wall so that it can't be seen unless we're actually in the conservatory. The leg/support will be held in place with a couple of G clamps in such a way that a solid modelling surface is quickly available but also quickly dismantled.

 

I'm in the process of cutting measured lengths of stainless 4mm rod and 2mm aluminium sheet for a few temperature/expansion/contraction tests. These will involve the freezer, room temperature and the oven to simulate extremes of venue temperature. The aluminium bridge deck should be ok across the aluminium frame but I don't want any differences with the expansion/contraction of the stainless rod to have any buckling effects on the bridge deck. The method of securing the rods to the deck will be reviewed if differences are found.

 

A useful selection of coach suspension units, wagon construction aids/detailing components and paint related items were gained from a morning visit to Expo EM north yesterday. Today has seen the finishing touches made to the new lightweight workbench in the conservatory and hopefully the last holes drilled/machine screws fitted in/to the Plymouth route bridge deck.

 

Dave

[Torr Giffard LSWR 1951-71]

Evenin' all,

 

Following on from a great summer of sunshine, holidays and welcome visits by Canadian family/American friends, work is once again underway with TG.

 

This clip

 

 

shows the Mk3 workbench, which is a compromise with the better half in terms of keeping the conservatory presentable and usable even whilst I'm working on components for the layout. It takes less than a minute to erect and is easily robust enough for many modelling tasks. 

 

The protruding rods beneath the bridge deck will be trimmed to overlap the 'masonry' arches by the required amount and then be clamped or individually strapped  down , with the ends free. This will allow for some heat expansion lengthways whilst keeping the viaduct securely in place. The stainless machine screws and thin/flat nuts have been stored in lighter fuel in order to ensure that they're thoroughly degreased and receptive to the Loctite threadlock,this should eliminate the risk of vibration loosening them over time. The protruding threads will be cut off with the disc cutter.  All machine screw heads will be made visible in the cork track base just in case access proves necessary at some point. 

 

The remaining views show the Plymouth route bridge deck with its four longitudinal 2m stainless rods securely machine screwed to the underside. The baseframe needs the polycarbonate river surface adding before the caissons can be added...this will be one of the next tasks. 

 

Our October charity coach trip/steam train ride to support the GWR after the expense of their recent problems/rebuilding is almost fully booked.

 

Last nights hot air balloon flight was postponed due to the unsettled weather. 

 

Todays progress has included fettling the Plymouth bridge deck to make it ready for fixing to its baseframe. Once all frame levels were checked across adjacent baseframes the bridge deck was machine screwed to the upper end plate at the station end and levelled relative to its frame. There is some flexing within the bridge baseframe  as it is moved, therefore two more stretchers will be inserted and secured across each longitudinal to cure the problem. The bridge deck can then be secured at the fiddle yard end and levelled along its length. A 5mm aluminium spacer will then be used to support the extremes of the polycarbonate river surface to match the 5mm dia. nylon bearings which will act as mid-stream supports.

 

Todays progress required the full size Mk 1 workbench with the 6' x 2' plate glass reference surface atop to be erected in the conservatory so that the Plymouth bridge frame could be judged level whilst (what transpired to be) the 3 new 'T' section stretchers were fitted to the underside. Quite a task removing the legs and transferring the frame to the back of the house. However, job done and definitely the way to go with the other river frames from the outset...the frame is now absolutely rigid and the bridge deck can be squared and securely fitted along its length with confidence. Chamfered corners on the new stretchers should avoid losing some flesh from the top of my head when moving around beneath the layout as the new pieces protrude lower than planned. 

 

Tomorrow sees a trip to the SVR Autumn gala as my dad's birthday treat...shame about 'Lord Nelson' & 'Sir Lamiel' but 'Cheltenham' and 'The Duchess of Sutherland' are worthy replacements.   

        

 

Dave

[Torr Giffard LSWR 1951-71]

Evenin' all,

 

This clip

 

 

shows current progress on the Plymouth bridge frame. The deck supports are to keep it level whilst the correct position is secured. The blue marker lines across the deck indicate the approximate extremities of the bowstring sections...each of the 3 of which will be almost half a metre long.

 

The new stretchers can be seen at the base of the frame.

 

The garden can be seen in its Autumnal colours....the earlier fencing resembled a hedge with Virginia creepers covering it. The new fence also has creepers and vines planted along its length but they haven't covered it yet.

 

Dave  

[Miss Prism]

Every new video of Dave's look to me more and more like a Fellini film.

 

That's a compliment, btw, for the avoidance of doubt.

[Isambard Kingdom Brunel]

AMAZING

[Torr Giffard LSWR 1951-71]

Every new video of Dave's look to me more and more like a Fellini film.

 

That's a compliment, btw, for the avoidance of doubt.

 

 

...I'm working towards less fantasy and more reality MP but thanks for the compliment. 

 

Dave

[Oldddudders]

Every new video of Dave's look to me more and more like a Fellini film.

 

That's a compliment, btw, for the avoidance of doubt.

Ah, yes - Fellini's Four-foot eight and a half?

[Torr Giffard LSWR 1951-71]

Aft'noon all,

 

It is the turn of the drawing board for a while now as the various measurements of the Plymouth route bowstring viaduct are decided. I have the basic dimensions but a considerable amount of proportional design work is required in order to recreate the character seen in the various photos of the structure. The diverging routes at the station end of the bridge are mirrored by the widening track centres at the Plymouth end on the approach to the twin tunnel mouths...this combination will mean a slightly wider bridge deck than on the prototype.

 

The basic ingredient for the 4 'masonry' arches is likely to be 1mm aluminium sheet...this will have good strength and shape once formed and machine screwed into place.  

 

Todays progress includes degreasing the wide river bed (aluminium sheet base of Plymouth bridge frame) with lighter fuel, mixing a thinned grey primer basecoat (new tin of paint always preferable) and brush coating the aluminium surface (currently drying pre 'flatting'). Gordon Gravett's MRJ articles now being re-studied. The 5mm dia. nylon bearing spacers will be superglued to the polycarbonate before the underside of same receives a thin 'riverwater greenish/brownish' wash of thinned enamel paint. Bonding the nylon spacer bearings to the polycarbonate means that any movement/flexing will mark the aluminium paint surface rather than the more visible underside paint surface of the polycarbonate.

 

Primer dry and all holes/machine screw heads etc filled and smoothed.  

 

River-water experiments underway inc. super-gluing nylon bearings to underside of polycarbonate, priming same and applying thin colour washes to start shading/grading the 'underwater' appearance. I'll take a view on the reflective qualities of the surface whilst 'flat smooth' once the various components are in place and all is dry. 

 

 

 

Dave     

[Torr Giffard LSWR 1951-71]

Aft'noon all,

 

The scenic challenge with TG is underway (all scenic work is currently experimental and liable to alteration at any time if the overall result isn't up to snuff)...these are the first few clips of creating the riverbed for the Torridge and supporting the polycarbonate river surface with 5mm nylon bearings. A thinned green/brown enamel mix forms the first two coats of the riverbed...this has been wet/dry sanded/flatted. The bearings have been primed and top-coated with several shades to see which is least conspicuous when viewed from above. Also experimental are the first few colour washes for the polycarbonate under surface. The bearings are concentrated in the areas where the caissons will stand..to ensure that there is no flexing of the 'water surface' once the bridge is in place. There will be a threaded centre (likely 4mm) running down each caisson, through the river and beneath the baseframe...this will act as an adjustment for getting the bridge deck absolutely flat and level. The brass outer (8ft prototypically) tube of each caisson will be attached to the threaded centre as it passes centrally through brass crosspieces within the tubes.  

 

 

All excess paint around the bearings will be blended/thinned into the washes as the experiments develop. Once I'm happy with the lower parts of the river I'll decide how to approach the river surface e.g. ripples etc of clear or tinted varnish and/or any surface treatment such as 'Kleer'.

 

This is the ultimate objective  http://www.flickr.com/photos/42855007@N00/5105167416/   . A tree lined broad/shallow river setting with reflected tree/cloud/skyscapes. 

 

Much experimenting to do.

 

Consigning the first 4' x 2' sheet of polycarbonate to be a test/experimental panel is already paying dividends. Loosely following GG's (Gordon Gravett's) article advice I'm trying out areas of different techniques...just to see what can be achieved and to allow me to choose from several results rather than simply trying one and sticking to it. The Tamiya varnish is a good choice GG...I've got windows and doors open to provide a through flow of fresh air...this is drying the varnish quite quickly which retains my surface design and prevents it spreading/flattening. I'm trying various brush styles, various brush strokes, various varnish loads on the bristles and various gaps between brush strokes. The refractive qualities of the wet varnish instantly and dramatically improve the appearance of the flat polycarbonate and bring the 'river' surface to life. 

 

Looking at various images of this wide, shallow river shows that the wind/breeze plays upon the surface in different ways, in different places, at the same time and creates varying surface conditions/patterns. In turn these catch the light differently and add more and more interest to the water surface. The river bed also affects the surface in shallower areas and produces yet more dimensions. 

 

Favourite effect at the moment is a mottled/neutral polycarbonate underside wash...this allows the greenish riverbed colour to be glimpsed among the gaps in the mottle...coupled with a pronounced ridge of clear varnish atop the polycarbonate. This produces a more complex and distorted water finish with some depth to it.

 

Further tests using a sponge to apply a thinned deep green, mottled underside layer, beneath a wavy interlocking varnish line/ridge effect are looking good too. The use of the sponge removes the lines in the mottle, whilst the long, wavy lines of varnish suggest flow and movement. There is a translucence through the various layers which is highlighted by the random way in which the varnish ridges reflect light...this suggests some depth/third dimension to the water. The nylon bearings are likely to end up bonded to the aluminium base sheet and painted at the same time as the riverbed...it is too much of a challenge to hide the points at which they are bonded to the underside of the polycarbonate.  

 

The challenge currently is to find the best green to thin and mottle to the underside of the polycarbonate. More lines will be added to the riverbed too...to add more interest and layer effect. 

 

The next tests will see blacks, blues and greens trialled as underside shades alternating with clear polycarbonate in long wavy lines.

 

Tinted varnish shades now. 

 

A P4 Dapol Beattie well tank is close....I'm currently reassembling one of the two on the workbench. Getting the main driving wheel bearings happily seated and correct mesh of the driving axles relative to each other is taking the time. Creating the clearance for the lead wheelset between the cylinders/slide motion is another challenge.

 

The sides of both sets of rears splashers on the well tank have had to be removed with a razor saw and scalpel in order to accommodate the main driving wheels....this allows the structurally weakened body structure to twist on the underframe. Two brass supports are now being fitted beneath the chassis to maintain the body square to the chassis.         

 

Dave

[Torr Giffard LSWR 1951-71]

Mornin' all,

 

Patch testing on the clear 4' x 2' polycarbonate test panel (in the search for a convincing 'wide river' technique) is providing valuable feedback regarding paint type, varnish type, ripple/wave effect, brush/sponge technique, bearing/spacer bonding, riverbed shade, polycarbonate underside paint application technique. 

 

This clip

 

 

illustrates some of the results which have pointed the way forward. 

 

Current 'favoured approach' is an olive drab/brown rust riverbed shade mix with a heavily thinned application of the same as the polycarbonate underside shade (applied using 1" and 2" artists brushes). The topside of the polycarbonate will be treated to gently waving multiple applications of unadulterated clear Tamiya varnish using a 5mm ish brush.

 

Learning 'cul-de-sacs' negotiated thus far include: don't mix enamels with the Tamiya varnish as the result is that the mix dries whitish; some paint shades 'thin' progressively less convincingly e.g. the dark green shade in the camcorder clip; bond the spacers to the aluminium sheet as the superglue/unpainted part of the bearing shows badly against the polycarbonate and is hard to mask.

 

Testing continues

 

A need for more olive drab/brown rust mix saw me call into the local hobby shop to collect some Humbrol tinlets (nearest Precision paints supplier 40 miles away)...unfortunately the colours were less convincing and didn't 'thin' in the same way. Frustratingly high courier rates with Phoenix (my preferred paint supplier) then resulted in more time spent checking current and future paint requirements/the placing of a larger order than intended....to offset the postage.

 

At 4.72mm the thickness of the aluminium in the heavier 'T' section will need a .28mm shim once it is 'sliced' to become the side supports/locking points for the polycarbonate river surface.  

 

Dave

[Torr Giffard LSWR 1951-71]

Aft'noon all,

 

The latest paint parcel from Phoenix containing more brown rust/olive drab river shades has arrived. Having test driven the first polycarbonate river panel with various samples/techniques, it was time to try a larger scale experiment. The river bed/5mm nylon bearing supports surface on the Plymouth bridge frame has been painted in the same well thinned brownish/greenish mix as the underside of the polycarbonate sheet. All paint has been brush applied in the direction of flow of the river, thin enough to appear opaque under the polycarbonate which allows the riverbed to be glimpsed through lines of flow in the paint. Reasoning that wind affecting the surface of a wide river lined with trees is likely to be blowing along the river e.g. from the open sea direction, I studied the ripple effect produced by this situation and it tends to be a large patch of wavelets/ripples across the river where the wind reaches the surface directly. Towards the margins and in other areas less exposed to the direct effect of the wind, there are other water surface conditions ranging from flat calm to small wavelets/ripples in different orientations. The rate of flow of the river is gentle, therefore the surface disturbance conditions immediately downstream of each caisson will be noticeable but not dramatic. The sediment load i.e. peaty deposits from the moors etc is fairly high...giving the brownish/dark water appearance. The varnish surface pattern is being added to as each previous application dries. Once I'm happy with progress then I'll fit the clamp/supports to the sides of the polycarbonate, to lock it in place.

 

     

 

Apologies for indistinct water effects on the camcorder clip...they show up far better on the TV screen and when viewed on the layout with the naked eye...I'll try some varied lighting angles to try and highlight them better.

 

As the various shades/varnish applications dry the likely end result becomes more apparent....another wash of a more greenish shade is going to be needed on the underside of the polycarbonate. The varnish whitens to some extent as it dries but then clears...the wavelets and ripples look more convincing as they are built up. 

 

The limits of the river in the area around the bridges will be low 'stone' retaining walls. In order to determine the line of these (and the curve of the river) I'll need to have the adjacent river panels available for positioning. Two more 4' x 2" polycarbonate panels have now been ordered from 'The Plastic People' and another batch of 'Khaki drab' tinlets have been collected.  'T' section aluminium for the Barnstaple bridge baseframe ordered.

 

The 2mm aluminium sheet deck for the Barnstaple line bridge is being marked out ready for 'slicing' with the disc cutter. Anyone considering this route should stick with Bosch high speed cutting discs rather than '4 trade' high speed ones...the latter cost the same but are nothing like as durable. The same 6' x 2" sheet of 2mm aluminium will provide the river bed on the Barnstaple bridge frame as well as the bridge deck.

 

 

Dave

[Torr Giffard LSWR 1951-71]

Aft'noon all,

 

Latest progress includes the measuring and slicing of the Barnstaple bridge deck from 2mm aluminium sheet (the same sheet will also provide the riverbed for the frame), the arrival of 2 more 4' x 2' clear polycarbonate sheets (excellent service from 'The Plastic People' again) for the adjacent river sections and the collection of sufficient aluminium section from Aalco, Knypersley this morning to fabricate the Barnstaple bridge baseframe.

 

  

 

Fortuitously, a recent picture discovery (taken from the train window as it crossed the bridge) of one of the last trains to Torrington, crossing the same curving girder bridge as the model bridge is based upon, has provided several important details about the construction of the bridge and will help greatly with the prototypical feel of the model. See

 

http://www.flickr.com/photos/53613503@N08/8301977566/in/photolist-dDBNGf

 

 

The caisson positions for this bridge (can be seen marked on the deck outline pre-slicing) will align with those for the Plymouth route bridge but there are twice as many (slightly smaller in diameter) due to the different style of construction. Three 2m lengths of 4mm stainless rod are ready to be machine screwed to the deck.

 

Latest progress has been the cutting to length of the four longitudinals for the Barnstaple bridge frame. The end plates were fabricated some time ago and simply needed recovery from the workroom. Later thinking re the only contact point between river frames being the edges of the polycarbonate sheet forming the river surface...to prevent dissimilar expansion/contraction of varying materials causing a gap in the river surface, which can't be closed under certain temperatures...will cause some aluminium to be trimmed from what would otherwise be mating components. The full width workbench/glass reference surface is once more in place in the conservatory, to ensure that assembly of the frame is square and flat. A current task is to source 6ft diameter equivalent brass tube for the caissons on the new bridge frame.  

 

Trevor Mann's new wagon book is imminent and will be a welcome book to sink into an armchair with.

 

Researching the construction technique options for the twin viaducts is throwing up a few dilemmas...the average viewing distance from them will be 4-6ft so individual rivets aren't top of the list, however, I'm extremely taken with the prototypical design of having the rails secured to longitudinal timber baulks along the 4-5ft length of the steelwork section on each bridge. Yes, it will take time to model, probably using brass sections painted in wood-like shades but the visual impact will be worth it.  

 

Latest stock on order are 2 of Bill Bedford's 10T LSWR brakevan kits for the early 50s incarnation of the china clay opens for Fremington quay workings. Two of the beattie sized consists will be shunted together at TG for a larger loco (M7 or cl 22) to work forward. 

 

Much of the Barnstaple bridge frame has been assembled today.

 

Dave    

[Torr Giffard LSWR 1951-71]

Evenin' all,

 

The Barnstaple bridge frame has now been fabricated and is clamped in place whilst the adjustable supports are made/frame locating dowels fettled. The mid frame support will overlap the adjacent frame too so that the river surfaces are held level to each other. The bridge deck can be seen temporarily supported in position.  

 

 

With grateful thanks I have received a video taken whilst walking across the Tavy viaduct. I used the pause and 'screen grab' option to capture 33 of these important detail images:

 

 

 

 

I'm investigating how to model the distinctive 'I' section & corrugated/ridged deck with associated timber beam structure. I can't bring myself to model either of the bridges for TG with a ballasted deck and hunger for the P4 version of the above images. Initial thoughts centre on the strength of the 2mm aluminium deck topped with rounded lengths of plasticard strip to represent the corrugated surface with brass 'I' beams for the main structural work and timber beams (disguised brass 'I' beams topped with cork which has been levelled across the twin bridges/whole twin structure trackwork with the levelling sledge). The plate glass reference surface will provide the initial required 'level'.

 

Latest progress is the fabrication of the 6ft x 2ft twin bridges - fiddle yards frame....this is transverse to the bulk of the frames and ties together the twin bridge frames. A large area within this frame will remain open to allow access to the twin bridges when the likely double scenic doors are swung back and secured.  

 

Dave

[Torr Giffard LSWR 1951-71]

Mornin' all,

 

Frame number 6 (6' x 2' bridges to fiddle yards transverse link) and the bar to accurately positioning both of the curving viaducts has now been partly fabricated and fitted into its position...locking together the two bridge frames. A fresh set of Templot prints can now be set out across the two bridge decks and the measurements transferred to the new frame/first supports bolted into place on the fiddle yards side. These measurements are made more important because of the accurate spacings required in the run to the linked traverser. See

 

 

The design difference (in terms of stretchers) with this frame will allow access to the fiddle yard end of the twin bridges in the event of a derailment etc. Twin opening doors in the sloping, wooded valley side on this frame will 'pin back' to give easy access. The track support decking arrangement will use robust 'T' section aluminium to replace the strength lost due to the absence of the stretchers.   

 

Dave

[Torr Giffard LSWR 1951-71]

Mornin' all,

 

More Templot work in progress at the moment to make sure that the 'Plymouth fiddle yard 'marries up' to the scenic section

 

 

The Barnstaple fiddle yard plan is also being adjusted....all fiddle yard roads will have 50mm centre spacings

 

The thicker vertical line marks the fiddle yard/scenic section boundary within the twin tunnels.

 

 

Both fiddle yards adjusted to the ends of the scenic section.

 

As with the scenic section the basic Templot plan (above) for the west end of TG is being prepared for printing by Stephen Freeman at Borgrail.

 

A sample of Stephen's latest handywork can be seen below...part of the approach to the Plymouth fiddle yard

 

 

 

The challenge for me is to build the track to a high standard.

 

Current progress centres on fitting the frame locating dowels to the ends of the bridge frames/adjacent transverse frame. Once I'm happy with the technique of reliably/accurately locating two adjacent river frames so that the 'water' surface is seamless then work on the bridges can progress. More fixings ordered from Westfield fasteners for the mid-river below baseframe supports.

 

Another solid day with Colin fettling the transverse frame to bridge frames locating dowels....quite a job clamping everything into level and correctly orientated positions to allow accurate drilling of the dowel positions but it is almost done now, just the 2 centre dowels to adjust and retighten.

 

Dave

[islandbridgejct]

Interesting work.

 

There are some useful bridge photos on Ciaran Cooney's 'eiretrains' site -

 

- here, at New Ross - http://eiretrains.com/Photo_Gallery/Railway%20Stations%20N/New%20Ross/IrishRailwayStations.html

 

- and here, further down the Barrow River towards Waterford - http://eiretrains.com/Photo_Gallery/Railway%20Stations%20B/Barrow%20Bridge/Irish%20Railway%20Stations.html

 

2 different ways of laying track on baulks.

 

I hope they help and look forward to seeing how you get on.

 

 

Alan

[Torr Giffard LSWR 1951-71]

Hi Alan,

 

....thank you for the images. Decision time for the technique is looming as I've now finished fitting the dowels between the 4 frames currently in play. 

 

This image from a currently unknown photographer

 

 

demonstrates the prototypical appearance of a typical corrugated LSWR route bridge deck.

 

Dave

[Torr Giffard LSWR 1951-71]

Aft'noon all,

 

Some pleasing progress today with the seamless positioning (height-wise & lengthways) of the first adjacent polycarbonate river panel. The combination of alignment in 2 planes, enamel shade and flow line came together using a technique of shared adjustable supports/clamps specific to the river frames. There are a lot more hurdles to clear but the crucial basics are working. A new length of adjustable leg will now be fabricated to bolt/machine screw to the centre of each shared underframe clamp/support...likely 2 per river frame joint. A dark foam strip will then be bonded to each side of the below river frame joins to prevent light leakage from making the joins visible. Now that the first join is secured the clear varnish ripple/wavelet patterns can be created to match each side of the polycarbonate mating surfaces.       

 

 

Already having the Barnstaple bridge deck to hand allowed its proportions to be marked on the river frame surface & extra 5mm nylon bearings to be bonded to the aluminium sheet in the best positions to support the brass caissons, to be positioned above. 

 

The new polycarbonate river panel then had its 'brown rust' underside enamel wash applied and can be seen drying prior to the 'US olive drab' second wash being applied. The wall mounted map of frames helps in knowing the curve/line in which to apply the washes. 

 

Another large paint and thinners order placed with Phoenix.

 

A spell as the 'Bishop's chaplain' beckons this evening as our local confirmation candidates are confirmed. 

 

1 inch dark foam   http://www.efoam.co.uk/foamsheets.php?gclid=CMu-_6L99boCFYzItAodNwsAKA   will be used between river frames beneath the polycarbonate join to prevent light leakage.

 

 

 

Dave

[Torr Giffard LSWR 1951-71]

Evenin' all,

 

More progress with fettling the first adjacent river panels on TG today saw any excess paint from 'mating' polycarbonate edges removed and most of any required 'touching up' carried out. The Tamiya varnish used for the ripple/wavelet water surface effects was then used to build on that already done on the Plymouth bridge frame and to start the work on the Barnstaple bridge frame. The gradual building of height can be seen as progressive layers are applied...the new/wet varnish stands high as a ridge but then flattens and loses some sheen as it dries. Layers will be added until the varnish forms a 'corrugated' effect on the most wind affected areas i.e. linking convex and concave curve forms so that there is no flat surface remaining...other effects will be devised as required.

 

  

 

Careful study of wind effects on river/wide water surfaces will now suggest how to vary the varnish applications in order to recreate a typical range of wide river surface conditions. Much experimenting to follow. The sponge for beneath the river panel joins is yet to arrive and there will be some tweaking of the paint finishes in those areas as it is fitted.   

 

The river panels will remain unfitted until I'm happy with the overall effect of all aspects (in case more washes etc are required), ...at which point I'll secure them to their respective baseframe.

 

Gordon Gravett's new modelling book on Grassland & Landscapes ordered from 'The Titfield Thunderbolt' bookshop.

 

The weather/local conditions...bright sunshine & water disturbance by moderate breeze...to be modelled on TG were visited on the Staffs Moorlands this morning....the local reservoir was convenient for studying a width of water similar to that of the river on TG and the effects of the breeze upon its surface.      

 

Dave

[Torr Giffard LSWR 1951-71]

Aft'noon all,

 

Good to see the postie this morning...delivering Gordon Gravett's excellent 'Modelling Grassland  and Landscape Detailing'...more armchair reading.

 

Progress today has centred on more polycarbonate underside washes and building up the surface effects on TG's version of 'the River Torridge'. Despite 2 washes having already been applied I wasn't happy with the green content of the 'river water' and felt that I had over-thinned the mixture of enamels initially....three more Humbrol tinlets of olive drab added to the No2 wash jar thickened the mix and gave strength to its green content. Both panel undersides were treated to an application, their mating edges cleaned of paint and the panels replaced onto their nylon bearing supports to dry. 

 

Next it was the turn of the surface ripple/wavelets to receive a couple more applications of varnish....8 more pots of Tamiya X22 varnish ordered from 'Antics' as it doesn't take long to get through 10ml.

Once the varnish had been applied it was time to leave everything to dry.

 

Attention then turned  to marking out the limits of the river to ensure that the appropriate surface effects were extended in the right directions. The large 1mm thick PTFE plastic sheet which had been sourced for the slide on the 'Linked Traverser' appeared suitable for slicing into 1 inch wide strips and blu-tacking into position as a basis/mock-up for the river wall sections on the bridge frames. One advantage of making the polycarbonate sheet area between the bridges the site of early/experimental work with surface effects is that it will be a relatively unobserved area of the river, whereas the areas on the viewing sides of the bridges will be continually under scrutiny...hopefully I will have polished some techniques by then. The plastic rod near the wall on the inside of the river bend marks the approximate extremities of what will be a mud bank/beach. See

 

 

for todays progress (although the camcorder is capable of superb results in many situations, it isn't giving an accurate colour representation of the river or of the translucence of the surface) .

 

Excellent bedtime reading at the moment is 'Traditional Crafts and Industries in East Anglia' - the photographic legacy of Hallam Ashley, due to its rich content of close up pictures of country life (1930ish onwards). The 1951-1971 period of TG means that farm implements/road vehicles etc have to date from (or just before) 1951 and reference sources such as this will help to get the balance about right. The book includes many working horse pictures but these would obviously be much rarer by 1971, similarly, the traction engines of 1951 would be long gone twenty years later, whereas the small lorries & Massey Fergie tractors new around the former date wouldn't look out of place around the latter. 

 

Today has seen the fittings for securing the polycarbonate sheets to the aluminium baseframe sliced from 3/16 aluminium 'T' section...the 4.7mm translation just needed a .3mm shim of sheet brass to match the 5mm nylon bearing diameter. Where possible the mushroom headed machine screws will be located beneath scenic detail beyond the 'waters edge'.

 

The two river panels are now machine screwed to the baseframes. The 1 inch thick sponge sheet arrived today and the first sections have been bonded into position with Evo Stik....there is no noticeable light leakage. The Plymouth route bowstring bridge deck has been detached again to allow the mounts to be lowered ready for the 'timber baulks' to be fitted.   

 

Plymouth route bridge design well under way now....fortunately, several clear side views of the Tavy viaduct bowstring sections are available which allows straightforward scaling of the side framing against the known bowstring section length....this gives useful proportional measurements to work to. In order to maintain the prototypical profile of the bridge the model will have a maximum deck depth (top of rail - bottom of side frame) of 14mm....made up of: 5mm stainless rod & fittings, 2mm aluminium bridge deck, 1.5mm for the upper half of the deck corrugation (strips of 1.5mm plasticard bonded to the aluminium sheet), 3mm thick polycarbonate strip to represent the timber baulks on which the rails/chairs sit (7mm wide & running the full length of the 3 bowstring sections) and 2.5mm of C&L rail chair & bullhead rail.

 

Once this is assembled and levelled then the brass sheet sideframes (4 per bowstring section) will be soldered to plating strips to form the distinctive arched box section outer framing.  

 

Latest arrival is a P.D. Marsh kit for a Morris Z van.

 

  

Dave