Ron Heggs

Modelling the 1877 viaduct bridge #2

This viaduct bridge is the Cornbrook Viaduct Bridge #2, which is some 50 metres west of Cornbrook Viaduct Bridge #1

This Google link shows the relevant juxtaposition of the viaduct bridges -

http://maps.google.co.uk/maps?hl=en&ie=UTF8&t=k&ll=53.474702,-2.256977&spn=0.002439,0.010278&z=18

Bridge #1 is to the right, whilst Bridge #2 is to the left. The long viaduct bridge to the North of these other two viaduct bridges is the Castlefield Viaduct 1894

The following drawings have been produced on CAD, with details taken from OS map, archive and present day photographs

The overall length is 1444mm, with a height to the top of the decorative pillars of 333mm

The length of the western span is 848mm, and the eastern span is 596mm

The width of the side cross-bracings varies between the end and centre sections of each bridge span

The bracing members are constructed as trusses in only one diagonal direction in each span

Details will be given as the construction proceeds

Cross-section and true-length side truss detail

Face and Side Elevations

Note: The pillars are elliptical in cross-section

To be continued - with construction as it proceeds

Modelling the 1877 viaduct bridge #1 - Continuation

Within each pair of the central braces a unique set of 4 pairs of shaped strip braces are positioned. Shown RED in the picture below

Deck Beams

The deck is produced from 40^th plasticard supported on deck beams in the form of RSJs. These are produced from 40^th x 7.5mm and 40^th x 4mm strips

The beams are fitted at the same centres as the vertical trusses. Four transverse beams made from 20^th x 5mm and 2.5mm strips are placed between each pair of deck beams. Additionally, angle strips are provided as deck plate fixings

Overhead Span Braces

Two overhead brace assemblies are positioned as shown on the bridge plan, and photo

Each assembly is produced from 20^th strips and 40^th plasticard

The bracings are positioned on both external faces of the two truss members, with the opposing braces sandwiched between the two truss members

The complete bridge structure is below

The structure now awaits some additional items, such as a handrail/barrier fixed to the eastern end of the north span, used to protect the open space between this viaduct bridge and the adjacent 1894 viaduct bridge

Painting and weathering will proceed at some time in the future when all the viaduct bridges will be treated simultaneously

The bridge deck will be covered with cork prior to track laying and ballasting

Yes, those are what I'm thinking of. It was rather inconsiderate of you to move to Spain before you built it, the exhibition managers may baulk at your expenses claim!!

 

Ed

Yes, but there was just no room in our 4 bed detached for a 10m x 5m layout plus access around it, and the milder climate here did beckon. We were lucky that the second villa we viewed had an underbuild which could house my intended layout, after the internal walls were removed. Building licence has been applied for and work should start early this coming summer

I think the prospect of moving the largest model structure once insitu i.e. the train shed, some 2200mm x 850mm would frighten even me

Maybe a professional video at some time in the future would be a more practical approach to enabling public viewing

Ron

Ron/Ed

I think that they are. Ed, are you referring to the often used scene with multiple wrought iron viaducts crossing a canal, over which crosses an arched, wrought iron, footbridge? It's featured in countless Manchester based dramas over the years. If so, that is the Castlefield basin, just behind the YMCA, close to Liverpool Road Goods Depot and the viaducts are those which, variously, served Central, the Great Northern Goods Warehouse and the line to Oxford Road. It's a hundred yards or so north of Deansgate, so on the opposite side to Central. I'm not sure whether Ron intends to model that far out but it's essentially the same run of viaducts.

Arthur

I can just about visualise where you are now. It just shows you how little TV I actually get to see. I believe the arched footbridge you mention is a later addition to the area, after the railways disappeared and before the Metrolink was introduced

The intention is to model as far west as the viaduct bridges extend

Model layout extent

Regards

Ron

To all those wondering why the cans of beer and not any other item

The beer is only 29 cents (26p) a can, so any damage is minimal if they fell off

Hi,

 

Superb detail, two questions if I may:

Are the components machine cut from the CAD program?

What adhesive / solvent do you use

 

Cheers

Mike

Hi, Mike

If I had a Laser Cutter, then yes I would use the CAD program. But no such luck, not at £2500+. So all the plastic is measured and cut by hand

You may have noticed in the last picture the bridge span is actually supported off two bottles of EMA Plastic Weld. Impossible to obtain in Spain, and difficult to get delivered by post to Spain. But there are amenable model suppliers

I do use Butanone for my track building, but again cannot be sourced in Spain, nor can it be shipped to Spain. But as it is essentially MEK, the local plumbing outlet sells this as a primer for uPVC and PVC piping before the application of adhesive, and it is cheap

The biggest problem using these solvents is the evaporation rate [it is slightly warmer over here than it is in the UK], when the bottle is open for even the shortest time. I am looking for a very narrow necked bottle, which should reduce this problem

1) what CAD package did you use, and was it wire frame, surface or solid modelling?

AutoCAD 2000 given to me when I retired

I use 2D wireframe, 3D wireframe, surface and solid modelling, whichever suits the job in hand

2) are the viaducts the ones that are always being shown on telly programmes set in Manchester?

If you are talking about 'Coronation Street', the answer is no. Their viaduct is just a brick facade

The nearest viaduct to Granada Studios is just north of Liverpool Street by the site of the Manchester & Liverpool Railway. The Castlefield and Cornbrook viaducts are south of Liverpool Street, and the LNWR viaducts to the West across the River Irwell

Thanks for your interest

Ron

Continuing construction of the Bridge Spans-

The vertical trusses have been completed and the South Span has been built

Assembly of span with just the vertical trusses and the end joists in place

Completed span. The central five trusses and the two end trusses are without vertical reinforcement plates

Closeup of span showing the gusset plates and diagonal bracings. Cross bracing is only to the three central trusses

In case you think these plastic structure are flimsy, study this next picture

No discernible deflection i.e. less than 1mm, and YES the cans are full and unopened, and NO I didn’t empty them immediately after taking the picture. That is a loading of 1 litre / 1kg

So the complete bridge with the two spans support the bridge deck should be able to support a minimum of 2 kg without any significant deflection

The next post will be the completed bridge structure with the bridge deck in place, in about two weeks time

CASTLEFIELD VIADUCTS - MANCHESTER

There are four viaducts at Castlefield, Manchester, built almost entirely in brick. Where they pass over railway lines and canal wharves, steel and wrought iron bridging structures employing various structural design arrangements have been used

Castlefield Viaducts -1847-1849 Manchester South Junction & Altrincham Railway, the one on the Altrincham line is the most southerly of all the viaducts and the other on the line to Salford/Eccles passes under the two Midland viaducts. East of Castlefield Junction the lines extend to Oxford Road and London Road (Piccadilly). (Presently used by Metrolink)

Cornbrook Viaduct -1877 Midland Railway, built adjacent to and the North of the 1849 Castlefield Viaduct, was used mainly for trains to the South and East. (Presently used by Metrolink)

Castlefield Viaduct -1894 Midland Railway, built adjacent to and the North of the 1877 Cornbrook Viaduct, carried the lines to the West, Liverpool, Cornbrook Carriage sidings and Trafford Park locomotive shed. (Presently disused)

The lines into Manchester Central Station, CLC Goods Warehouse and GNR Deansgate Goods Warehouse used the two viaducts built by the Midland Railway

The 1877 viaduct has two separate bridge spans, whereas the 1894 viaduct is a single bridge comprising eight individual spans - The 1894 viaduct bridge structure is already work in progress, see Gallery link

Google Maps link :

http://maps.google.co.uk/maps?f=q&source=s_q&hl=en&geocode=&q=Castlefield&sll=53.800651,-4.064941&sspn=22.297654,67.456055&ie=UTF8&hq=&hnear=Castlefield,+Greater+Manchester,+United+Kingdom&ll=53.4746,-2.256306&spn=0.00273,0.010278&t=k&z=18

Modelling the 1877 viaduct bridge #1

This bridge spans the MSJ&R lines to Salford, and is built on the skew. The northern span runs east-west and has a length of 150ft (600mm). The southern span runs at an angle of 3.1° from east to west, and is 166ft (664mm) long. The resulting bridge deck is 84ft (332mm) wide at the east end, and 66ft (264mm) wide at the west end. The skew angle is -63° from North. The lines run on a curve between the bridge spans

Plan of bridge without the two span braces

Plan of bridge with under deck steel dimensions (4mm scale)

North and South Spans - south elevations

3D view of South Span

3D views of Vertical Truss Structure with strengthening plates

Vertical Truss Structure without strengthening plates - Modelled in plastic

Plastic Modelling in 4mm scale

General comment

Butanone/MEK (Methyl Ether Ketone) is used for temporary assembly where necessary

EMA Plastic Weld is used for all permanent/final assembly

Templates and jigs were not used

Vertical Truss Structures

The structure is built using four pieces of Evergreen 291 - 60^th angle section, each 59mm long, with a 10^th x 40^th x 7mm long strip sandwiched between them at each end. Eight diagonal strips of the same section 7.5mm long are fitted at 5mm intervals between two of the angle sections. This is repeated for the other side, so that the diagonal strips appear as X’s, when viewed from either side

Using a 0.55mm drill bit, holes are made through each pair of diagonal strips forming an X, spinning the drill bit with finger and thumb. Pieces of 0.5mm plastic rod 2mm long are fitted through each pair of adjacent holes, to represent the fixing bolts

Additional fixing plates/shims, 20^th x 100^th x 7.5mm long, are added at the end of each pair of angle sections

When constructing structures with strengthening plates, two strips 20^th x 4mm x 59mm are fixed instead of the four fixing plates/shims

The north span requires 13 in total, six without strengthening plates, and seven with strengthening plates.

The south span requires 15 in total, seven without strengthening plates, and eight with strengthening plates

South span – Lower beam

Lower Span Beams

The lower beams are constructed from two vertical strips 20^th x 7mm, fitted top and bottom with strips 20^th x 60^th. Strips 10^th x 30^th are fixed vertically within the angle formed by the top and bottom strips

Spacer plates are made from 20^th plastic card 7.5mm wide x 7mm high with strips 20^th x 60^th x 7.5mm fitted to the bottom edge

The two channel beams are fitted with the spacer plates at 40mm intervals. On the north span the first spacer is 30mm from the west end, and the last spacer is 50mm from the east end. The dimensions for the south span are 32mm from either end. The plates are fixed flush with the bottom of the channels

The ends of the each beam assembly are fitted with pieces of plastic card 20^th x 8mm x 11.5mm

Upper Span Beams

The upper beams are constructed from two vertical strips 20^th x 7mm, fitted at the bottom only with strips 20^th x 60^th. Strips 10^th x 30^th are fixed vertically within the angle formed by the bottom strips

Spacer plates are made from 20^th plastic card 7.5mm wide x 7mm high with strips 20^th x 60^th x 7.5mm fitted to the bottom edge

On the north span the first spacer is 20mm from the west end, and the last spacer is 40mm from the east end. These dimensions are 20mm from west and east ends, on the south span

A strip of plastic card 20^th x 11.5mm wide is fixed across the top of the two channels with 1.5mm overhang along each side. Strips 10^th x 30^th are fixed vertically to each side of the assembly, within the angle formed by the top strip

End pieces are not required

Sloping End Beams

Following the differences shown on the drawing elevations, these are built in a similar fashion as the top beams

Next step is the assembly of both North and South Spans

Work in progress

..... to be continued

Good stuff Ron

 

How long is the station itself? As the roof is 6ft + long is a section to be removable to get to derailments etc?

 

Cheers

 

Jim

Sorry Jim, had so many comments I missed your question, have just answered similar question from Michael Delamar

If you have any further questions please ask

All the best

fantastic work Ron,

 

sorry if its been asked before, will you be doing the whole roof, a freind of mine is building Liverpool lime st in 4mm and has decided to have a few sections removable/open to allow people to see in, I think having the entire roof would be good even if its only practicle to use it when taking photos etc.

 

Ive

often wondered if the roof at Manchester central shared any design similarities with the now demolished roof at Liverpool central, as if a model were to ever be made, someone could take info from the surviving roof at Manchester

 

 

look forward to seeing more pics

 

cheers

 

Mike

The whole roof is being modelled, overall length including frontage canopy will be 2200mm long and 850mm wide. Still deliberating on whether to complete clad and glaze the roof and have webcams installed for viewing interior on computer screen or leave completely unclad/glazed. In either case will probably have 2 bays over loco release area removable just in case of a problem. Will arrange for auto-uncoupling of loco from lead coach under normal operations

The roof of Lverpool Central was smaller in length and width, but did have a similar basic steel design above eaves level, but of a much lighter construction

The following web link has a number photos of the roof of Liverpool Central

http://www.disused-stations.org.uk/l/liverpool_central_hl/index.shtml

This is phenomenal! How did you become so good at model making? Those structures look professional quality.

Although I have an engineering degree, and was chief engineer for almost 30 of my 38 years in one the largest construction companies in Europe, and also wrote engineering design software during 25 of those years, my passions have always been mathematics, painting and drawing

I had never attempted modelling until this project, that is why I built a trial model of part of the station. Just to see if it modelling was within my abilities, and was up to a standard acceptable to myself

I suppose my whole background has brought me to this most enjoyable pastime

Thanks for all your enthusiastic comments. Hopefully, this post will answer all your queries

I retired in Jan 2003, and started research and trial builds in Feb 2004. Modelling all the various station structures, such as the roof, platform canopies, signal box, bridges, viaducts, pubs, shops, canal locks, etc. and some trackwork has taken so far about 6 years. This last year has been taken up by our move to Spain and getting a good architect to remodel our villa underbuild into one open area without pillars or internal walls for use as a railway room. Hopefully by the end of summer this year I can start to build the open frame baseboards, and really start to build the railway

The gables are reasonably rigid, they resist twisting and will take a good load, including an inadvertent fall without damage. The spans when tied together with the transverse beams are also reasonably rigid. I think this says a lot for the prototype structural design

The past few years has put a squeeze on plastic strip and extrusion supplies, as most model shops only carry small stocks, and re-ordering is a two to four week cycle. But regular bulk orders usually spur the suppliers to deliver

Statistics - On the station roof structure alone there is in excess of 35,000 individual pieces of plastic strip/extrusion. That has taken some cutting, and a large number of replacement knife blades. Although the roof is not yet complete, all the individual pieces have been cut and stored in separate containers awaiting the final push

A typical span use to take about 8 hours, including the individual cutting of strip. But after the bulk cutting project, a span now takes under 3 hours

The gables each took about a week, plus 2 days for the glazing bars and glazing

Usually, I shuffle between building tasks on different individual structures. This keeps the mind alert and stops the feeling of lack of progress from building up

The Deansgate Bridge with the electric signalling gantry which is a mixture of foamboard, mount board and printed card brickwork, with plastic for the ornamental bridge steelwork and the gantry, and re-modelling the Eckon LED signal with hidden wiring, took in total about 10 days. That includes the CAD drawing and total build time. Some of the incidental buildings, such as the Crown Hotel on Deansgate also took about 10 days, whereas the Castlefield Viaduct took in excess of two weeks, and is an ongoing project

I have started a trial build of the original Castlefield Viaduct, which spans the MSJ&R into Salford, and is far more detailed, but it is only a single span

But today, I am re-building the Station Restaurant block, which was part of the trial build, and will incorporate correct dimensions and detailing, and plastic strip built windows (there is only 20, so not worth going for etched brass)

Awe-inspiring! And CAD looks a very useful modelling tool indeed! This magnificent structure alone is worth a whole Model Railway Journal feature. Are you modelling a specific period?

The general period is 1953 thro' 1965

The original station roof cladding/glazing was replaced in 1952

Station approach trackwork was remodelled and re-signalled in 1958

I do have a few locos outside that time frame, such as LMS 10000, LMS Black 5, Prototype Deltic, etc.

I hope to add a Midland Pullman to the collection when Bachmann delivers late this year

Further work on the station structure has been suspended since last January when I moved to Spain. Until the Railway Room is completed I am not able to build the baseboard to support the complete station

Work continues on the Station Walls internal/external faces and buttresses. Building of the Castlefield viaducts also continues with additional structural detail being added. Some of the under bridge support steelwork is being modified to match new photograghic details

A number buildings adjacent to station and the approaches are still in boxes, and must wait for future exposure and photographs

Will continue to add images to the gallery and the main topic