jim.snowdon

And on the Croydon Tramlink system, at Mitcham, where earlier buttressing to a failing retaining wall precluded normal double track, and interlacing saved two sets of switches and mechanisms.

However, the piece de resistance of track interlacing probably has to be this specimen, which was installed on Stuttgart tramway system in 1997. Not only is it a crossover within the interlace, but because Stuttgart were installing dual gauge track as part oftheir phased changeover from metre to standard gauge, it is interlaced dual gauge as well. The crossover is still there, albeit now standard gauge only as the changeover from metre gauge has been completed. There are, to judge by the cab videos on youtube, still quite a few dual gauge junctions still in place on the street sections of the system simply because it is impractical to remove the metre gauge rails other than when the whole junction comes up for renewal.

Both pictures appeared in the June 1997 issue of what was then Light Rail & Modern Tramway magazine.

Jim

What you came across in Manchester is not uncommon in tramways and can be decided by several factors. In this case, the obvious one is that should the tram driver have to manually operate the points, he can do so without having to stop the tram across the road. It can also be found, in mainland Europe, where the tram stop is immediately before a junction, as it lets a following tram set the points automatically whilst the first tram is still at the stop. It is effectively barred in the UK by the Disability Discrimination Act, as the offset makes it impossible to meet the statutory requirements for the tram/platform gap. (European legislation for the disabled, actually Persons with Reduced Mobility, is more practical than its UK embodiment.)

Alternatively, such an arrangement can be used simply to get the points out of the carriageway, especially where there is turning traffic.

Jim

Liskeard & Caradon Railway - stone block sleepers and T (flatbottom) rail, probably as constructed in the 1840s. Interesting to note as well that the fishplate joints are staggered, a practice which is still followed in the US but otherwise virtually non-existent in Europe.

Jim

HI Peter

It is not very often that pre -etched holes align correctly and I wish designers would leave them out so that you can do them yourself, but filling and redrilling is not a big issue.

Sandy

Sandy,

There are occasions where I would agree with you, but these often involve kits whose design quality is suspect. I haven't found it an issue with well designed kits, and with the geometric complexities of Belpaire firebox boilers, having the designer work out where the holes should be on the boiler barrel and the firebox does make life easier. The latter aren't boilers where you can simply scribe a line along the length of the boiler as the handrail knobs are mounted at different angles and heights so that the handrail remains level.

Jim

And so will I, both days.

Jim

Duly done,

Jim

Wot! No t-handled box spanner for driving the coach screws home in the chairs? Every good p-way gang should be in possession of at least one, and if the ganger was doing a bit of levelling (usually inevitable at joints) it might take more than a bit of doing to get that jack kunder the rail without its foot fouling the sleepers that need lifting. In the earlier years of railways, and through into the 20th century, the usual tools for lifting track were either a screw jack (whose foot went under the rail) or an iron-shod lever (of considerable proportions) that used the ballast in the four-foot as a fulcrum. There are two excellent pictures, which I can scan and send off-group if required, in Janet Russell's book "GWR Company Servants". Apart from that, I am not quite certain why a p-way gang should need a grindstone - the only things that could need sharpening on a regular basis would be the auger bits used for drilling holes in new sleepers for the chair screws.

Jim

Martello (via Warren Shephard) did an excellent set of castings for both the four cone ejector and the special pipe/handrail brackets. As far as I am aware they are still available, but, according to Warren's website (which may not be up to date) there are some uncertainties over supply since the original proprietor of Martello passed away.

Hobbyhorse also list a similar set of csastings, including the brackets, in their Tony Reynalds range, all of which would have saved messing about with modifying handrail knobs.

Jim

The good engineering reason for putting the connecting rods inside is to allow larger cylinders to be accommodated within the loading gauge.

Jim

Sandy,

As you say, this is something of an old chestnut, although I think there is little doubt that something would be useful. All to often, reviews that have appeared in the press lack depth and gloss over problems by telling the reader that "with a bit of care/fettlling/etc." it will make a good model.

There has, in the past been some discussion between myself and various members ofthe Guild over a simple scheme, not dissimilar to the approach you are advocating, where members can rate kits on a simple system over a limited number of categories. Looking back over the correspondence, what I had proposed was:-

- Accuracy (of manufacture), ie did all the parts fit together
- Buildability - easy or difficult
- Quality of parts (especially castings) - good, bad or indifferent?
- Complexity, ie was it a simple kit with few parts, or a complex kit with a great many detail parts?
- Appearance - when finished, did it look the part (not was it dead accurate to the prototype)
- Value for money - good, bad or indifferent?

each scored on the basis of 1 - 5, ie 1=terrible, 5=really good.

Any more than is liable to become too complicated and diluted by irrelevant data. The key, as you have identified, is reducing it to a exercise in box ticking, not writing; too many people find writing a chore and will fight shy of saying something that might be out of turn. There also needs to be a degree of anonymity, at least as far as anything that appears in the public domain is concerned.

The one worry comes from the manufacturers themselves, who are frightened that one rubbish review (rating) from an inept builder builder will adversely impact on their sales. I think that that is a valid concern and had proposed that the rating for any particular kit is not made public until there are a minimum number of reviews, say, five, so that the effects can be averaged out. That is, after all, essentially the same as the system ebay use to rate sellers, based on buyer feedback.

Jim

David,

To quote - "I do take the point that modellers should reasonably expect 'this' and that they should reasonably expect 'that' when they purchase a kit for a good number of £s but I still say: look, inspect and manage your expectations."

I quite agree, but it is far from easy to look at a set of etchings and tell if the assemblage is a kit that will go together or one that will not without a fair bit of scratchbuilding. About the only method with any certainty is reputation, most of which is passed on by word of mouth rather than by good open and honest reviews in the pages of the model press and publications like the Gauge O Guild's Gazette. It is then up to the prospective builder to decide what sort of risk he is about to take on relative to his skill. There are kit manufacturers, not all of them still extant, that I would not recommend to a novice, but which become practical propositions, even interesting challenges, once greater skill has been acquired.

Jim

Sandy,

An erudite explanation of the pitfalls of an Ace kit - and why I think they are not kits for the beginner. But, the fact that the fundamental faults can be corrected can never be considered an excuse for the poor design in the first place.

Jim

Fair comment. I have to admit that when I first looked at the pictures, I read them as appearing to show 3 truss rods, which struck me as odd. Looking again, what I think happened is that I wrongly interpreted another underframe fitting, possibly the steam pipe drain valve, as one of the queue posts on the far solebar. Oops

Jim

Very nice, but two minor niggles. Only three truss rods? Shouldn't there be four, one to each solebar and one to each of the two centre longitudes?

The other - I appreciate the carriages are brand new, but it looks as if the shop lad was sent round with the Brasso to polish up the door and commode handles - a little too zealously, perhaps.

Jim

Jim H was by no means the only offender in this respect, and sadly their efforts are still being inflicted on newcomers to the hobby, often under different labels to the original product. On the other hand, I have every respect for people like Jim McGeown who continue to ably demonstrate that you can design economic kits that do go together. If only modellers would complain more when it comes to the "duds".

Jim

More like plain badly designed, although that's not untypical of some of the early kit designers. There are others who did a good job of design, and still do.

Jim

Not by definition, although DC2 & DC3 were very easy to adapt to vacuum braking. At the start ofthe 20th century, most vacuum braked wagons with special types like the Fruit and Meat Vans, which had the carriage vacuum cylinder arrangements along with clasp brakes and, quite often a simple lever hand brake operating on one brake shoe only.

Jim

What you have under the cattle wagon is the DC2 variant of the Dean Churchward brake. Legitimate but not very common and short-lived as they were easily converted to DC3 pattern to comply with the Board of Trade edict on right-handed bake operation.

Jim

With regards to the southbound signals next to Hammersmith Road Bridge, it does, thank you. I hadn't considered that the junction for Earls Court was that close and that it would have had a splitting distant. Since both distants have to be interlocked at the signal with the home, it must have made for some interesting lever arrangements at the bottom of the signal post. I'll have a closer look at the Reading Show next month.

Jim

What has me puzzled is why the right hand arm has only a distant on it. There is doubtless an explanation, probably connected with Addison Road having had more than one box. The middle post is patently the through route, in which case I would read the top arm as Addison Road North's Up starter and the distant under it as Addison Road South's. The left hand post presumably works on the principle that asall trains would be stopping, or at least at restricted speed, there is no purpose to a distant. It is the right hand post that is the puzzle, as with only a distant, there is no signal protecting what is obviously a diverging movement.

Jim

I do, Sandy.

I had to take a millimetre out of the chassis because the builder (not its owner) had set the frames with the bushes precisely 29.2mm across the faces. Great for straight test tracks but not much help on anything less than the most gentle of curves.

Jim

Ozzy0 can make his flywheels without having to worry about commercial costs; for mass production, it is far easier, and therefore cheaper, to make a component such as this from a single material in one machining operation. Hence, the one-piece brass flywheel.

Jim

It is also permissible, within limits, to split what would otherwise be a very long timber, so that the left and right rails were on the ends of abutting, but unconnected, timbers. When this was done, the requirement (from memory) was that there could be no more than one split timber between timbers that retained the gauge, but I have come across an example where the proportion was 1 gauging timber in 4.

There are several archive films of track renewal on youtube that are worth looking at - the two that come to mind first are "Junction Renewal", which covers the construction and installation of a complex piece of S&C at Chester, and another that covers the complete renewal and remodelling of the St Pancras throat in 1947.

Jim

It's very pretty, but the timbering where the two turnouts and the diamond abut each other needs a bit more thinking about. Apart from the length of some of the timbers, there are going to be a lot very close together, so much so that in the full size, they would become difficult if not impossible to pack correctly. The snag for modellers is that other than under crossings and switches, there are no strict rules for laying out the timbering; it becomes a case of applying experience in ensuring that the rails are adequately supported whilst at the same time building in sufficient maintainability.

Jim

It's very nice, but the ability to maintain tread support does depend quite critically on the spread between the intersection points of all three routes. Michaels does appear to have arranged (or as likely, the prototype did) to have all three tracks intersect at the same point. The engineers on the GWR do not seem to have been quite so diligent, but equally, may have faced more constraints. Having continuously supported bridge rail would have made the insertion of blocks or plates to support the wheel flanges easier than with chaired track.

But, I have come across references in early 20th century track engineering textbooks to the deliberate (as against ad hoc) use of packing blocks in the crossing flangeways to support wheels through crossings. Apart from providing support that depended on who worn the wheel was, there were disadvantages that would appear, ultimately, to have outweighed the benefits.

Jim