Fishplate conundrum

[Rustyrail]

Does anyone know if anything other than four bolt pattern fishplates exist on standard gauge bullhead track (or on industrial track)? I'm thinking in terms of two or three bolt. The reason being that I've made a small mistake with the position of two of my chairs on a common crossing where there is the electrical break in the rails, not leaving enough room for a full fishplate! I can't position the chairs differently because they will stick out over the sleeper edge. Just for your info, the turnout in question will be part of the industrial "complex" on my layout so the traffic over it would be light. Any prototypical suggestions?

Cheers
Simon

[grovenor-2685]

In such an industrial context the maintainer may well just burn off the ends of the fishplate to make it fit. I would think that perfectly plausible.
Fishplates with only two bolts were used in a number of areas, I remember a stretch on the Marple - Macclesfield line near Marple Wharf Junction. They were used with close spaced end sleepers in an attempt to better support the joint but I think the loss of support from the fishplate outweighed the benefits from the close spaced sleepers and they were not continued. IIRC this gets a mention in one of the Digest Sheets written by Derek Genzel.
Keith

[martin goodall]

The GWR briefly tried using 2-bolt fishplates in the 1930s (and I think they are referred to in 'Track Topics' - one of the Railway Books for Boys of All Ages published by the GWR). However, I learnt from a retired GWR PW engineer, that the divisional engineers were busy replacing them with 4-bolt fishplates even before that book was published!

So maybe this doesn't give you much excuse for your 2-bolt fishplates. But does that really matter? Will anyone notice if you do have one or two two-bolt fishplates? Perhaps we shouldn't worry about such insignificant details.

[Rustyrail]

Many thanks for your replies Keith and Martin,

It's good to know that two bolt fishplates have been used in reality, even if sparsely. What you say Martin is true of course but it's that niggling feeling that it's not quite right, especially as one of the reasons for choosing P4 is to get it all right. However, as this particular turnout will be quite overgrown with grass and weeds, the anomaly won't be easy to spot.

Cheers
Simon

[LesGros]

I was informed by Len on the P4track Co stand, that 2 bolt fish plates were often used to join sections of checkrail on tight curves, and presumably bridges. This was modelled on the checkrail curve sample they used to demonstrate the wider checkrail flangeway chairs that they have available.

regards

[Rustyrail]

That's very interesting Les. I'm also curious about the wider check rail chairs produced by the P4 Track Company as I recently bought some check rail chairs from them. These seemed to have a wider clearance than I would have expected for P4 between the stock rail and the check rail (when measured with a roller gauge). I presume these are the chairs that you refer to above.

Cheers
Simon

[grovenor-2685]

The wider check rail chairs are intended for use on curves with gauge widening or for such things as guard rails through level crossings where the rails do not have a checking function.
Keith

[LesGros]

Keith,

Ah ... I strongly suspect the error of terminology, Check rail instead of Guard rail was mine not Len's.

Thanks

[grovenor-2685]

Nothing wrong with your terminology Les, check rail chairs is correct, when track is gauge widened for curves the gap between check rail and the adjacent running rail (flangeway) is increased by the same amount as the gauge widening. This is because the important setting for the check rail is the 'check gauge' which is the distance between the checkrail and the opposite running rail.
In cases like level crossings the rail is not required for a checking function but just to keep a good flangeway through the road and the extra few millimetres clearance makes sure the back of the flanges don't rub, so guard rail is more appropriate in this case.
Keith

[allanferguson]

Recently using, for the first time, Exactoscale Check Rail Chairs (sic), I was a bit taken aback to realise that some of the chairs on the sprue are set for a wider flangeway, which I take to be for the flare at the ends. There's nothing in the exactoscale instructions (that I can find) mentioning this, and it's easy to mix up the two sorts of chair.

Allan

[grovenor-2685]

Allan, that is a different chair again, and should be in both left and right hand versions as they hold the flared part of the checkrail.
Just looked at the B8 Instructions on the Exactoscale website, here is what it says about check rail chairs.

9. ‘Load’ each check rail with check rail chairs. Note that the keys on the CC chairs should all point
in the direction switch -> crossing whilst the CCR and CCL chairs have their keys pointing towards the
middle of each check rail. Space the chairs on each check rail to fit correctly on timbers 27 - 31.

The chairs you are talking of are the CCR and CCL.
The chairs that were under discussion above are

4CH 403A 4mm scale check chair 0.8mm flangeway (100)

Keith

[allanferguson]

Keith, thanks for the amplification. I hadn't read that section. I'm building (very) pre group track with interlaced timbering,loose heel switches, etc, so the P4 Track Co kits are not directly relevant, and I'm using what bits are available and can be made to suit. At least not many people can argue with me about 1880 Caledonian Railway track!

My apologies for hijacking this thread.

Allan

[Rustyrail]

Not at all Allan! It's interesting to read your comments.

Cheers
Simon

[andrew jukes]

Perhaps a few words on the history of our check chairs and on our plans for them would be helpful.

Making check chairs that give the required flangeway was the hardest task in producing the P4Track Co turnout kits. It took several attempts and the 0.8mm flangeway chair was in a sense a useful mistake along the way. The designations on the mouldings give the game away.

The check chairs were always intended to provide a set for a turnout with check rails spanning five timbers, so each sprue contains ten chairs, six standard CC chairs and two left hand (CCL) and two right hand (CCR) 'splay' chairs. The sprues have these designations on them (in very small writing!). Inevitably, if the chairs are used for continuous check rails which will have splay chairs only at the extreme ends, there will be wasted splay chairs, the proportion wasted depending on the length of the continuous check rail.

The 0.8mm chair is helpful because of the need for a wider flangeway on gauge widened track. Arguably, for typical model layouts with curves of 1000 - 1500mm radius where gauge widening of 0.2mm+ might be appropriate, a 0.9mm flangeway would be required. The best that can be said for the 0.8mm chair in such circumstances is that it is better than a 0.68mm chair.

A problem with both 0.68mm and 0.8mm chairs is that they do not fit the rail section very well, holding the foot of the rail too tightly. This has several bad consequences - when rails are inserted in the chairs, their bases become cambered, the flangeway opens out and it becomes difficult to fit the chair to the pip on the sleeper. If you don't get the chair base flat, the flangeway will be wider than intended and when you do get it flat, the chair grips the foot of the rail so tightly it becomes very difficult to move it along the rail to adjust its position. It has long been an ambition to produce an improved chair that fits better.

This seems to have taken forever but we are now close to success. When we are there we will produce an improved 0.68mm P4 chair, a 0.58mm S4 chair and a wider chair suitable for EM and 'finescale' 00 (with a 0.95 - 1.00mm flangeway). This wider chair will provide another option for gauge widened P4 track and will be much easier to use (as it will be easier to adjust its position on the rails) than the 0.8mm chair (which will continue to be available). The improved chairs will be in the same 10-chair sprue format. No promises on timescales for these improved chairs, though.

Regards

Andrew Jukes
Exactoscale Ltd.

[essdee]

Interesting indeed - especially Martin's reference to GWR usage of two-bolt fishplates. I have been surprised to encounter photos of Somerset and Dorset track on the Bath extension relaid by the LMS with 60ft rails, presumably during the 30s, which only had two-bolt fishplates. This was the era of the Black Fives replacing 4-4-0 types on through passenger workings, and generally heavier loco and rolling stock axle loadings, so I presume they were placing sleepers close up to the rail ends to try and support the joints more firmly. I suspect the sinuous nature of the Bath extension caused problems with threepenny-bit curves after a period of wear, and that the PW gangs were mopping up a lot of overtime. I think some two-bolt fishplates survived into the 1960s though - Midford I seem to recall as one example.

So yes - there certainly were precedents!

Steve

[Rustyrail]

Many thanks Andrew and Steve for your posts; both very helpful and interesting.

All the best
Simon