On My Virtual Workbench...
- Thread starter S-Club-7
- Start date
Stevesopwith
Western Thunderer
To key or not to key.... that is a question of construction; but cosmetically, allowing for a range of local variation, GER ash ballast generally left the chairs visible, even when over the tops of the sleepers.
adrian
Flying Squad
I don't see the problem, I believe he's got a willing volunteer to do the trackwork for him!
S
Simon Dunkley
Guest
S0d the keys: what about those magnificent signals - calling on and shunting arms?
The location is obviously Cromer, but what is the date? Circa 1910?
The location is obviously Cromer, but what is the date? Circa 1910?
S
Simon Dunkley
Guest
I can't believe that everyone (especially me) let that one pass...
Buckjumper
Flying Squad
Well we had quite a discussion about the pros and cons, and we four (PJH, S-C-7, Mudhen and I) agreed that there were advantages in not having to sift through separating left-handed chairs from right, or make good rail and/or chairs to allow the passage of the rail past the keyway, plus the advantage of being able to quickly lay only one in half a dozen sleepers or so to quickly build up the alignment of the track, and once all was approved by the PW foreman the remaining sleepers (with a jig-fitted chairs!) could be quickly and simply slid into place, the keys banged in and Bob's your uncle. I'm sure there were other good reasons mooted, but the pork pie was somewhat distracting.
Despite Steve's lovely photo it's actually out of period for BF; the presence of the Diagram 224 50' 1st/3rd non-corridor composite with luggage and lavatory facilities puts the date back to at least 1906, by which time the old Victorian GER method of deep gravel ballasting over the keys on the outside was virtually extinct (a method also used by the Midland as it was supposed that the ballast would help keep the keys from working out).
Apart from that, S-C-7 mentioned to us the financial aspect which (though I've forgotten the figures) definitely precludes these chairs from being used in any great number on BF, so I'm thinking of using them in an easily visible siding on the spectator side of the boards where the ash ballast has been tamped down by foot, hoof and rainfall.
Buckjumper
Flying Squad
Ta. Worth taking that into consideration.
Buckjumper
Flying Squad
28ten
Guv'nor
I have hit a similar problem with 1/32 chairs - cost. as you suggest using small numbers is just about practical but doing a thousand or more is bloody expensive. in theory you can resin cast them but thy are fragile (even in 1/32) and the key is in effect driving a wedge between the rail and chair causing further stress and splitting.
Buckjumper
Flying Squad
I think we agreed a small test track was worth doing to see what a can of worms we've opened problems arise and how they might be overcome. If the stresses on the chair jaws are too great then that might turn out to be a bit of a head-scratcher.
S-C-7 is the genius amongst us, and may have already computed on his fingers the yield strength/ultimate tensile strength, or whatever it's called (I had to wiki that last bit and it still went over my head).
S-C-7 is the genius amongst us, and may have already computed on his fingers the yield strength/ultimate tensile strength, or whatever it's called (I had to wiki that last bit and it still went over my head).
S-Club-7
Western Thunderer
Many thanks.
The 3/32" taper scales to about 0.05mm. I'll have to emboss a "T" on the thin end and another "T" on the thick end so that they can be inserted the right way...
S-Club-7
Western Thunderer
If you push too hard then the acrylic chair jaw will break, simples. So insert gently (where have I heard that before?) or we can get somebody to laser-cut the keys in cardboard...
28ten
Guv'nor
I found thin balsa to be the most forgiving material, although card might just work. I lasered a strip and plonked them in the chopper.
My general conclusion was that it is a marginal gain, but that it is possible to do it, and that if you have someone else to fix them in place it is a marvelous idea
Buckjumper
Flying Squad
In colour terms balsa isn't too far from fir either - a slight reddening and darkening.
Dave also forgot to mention the scale keying hammer...
Dave also forgot to mention the scale keying hammer...
Dog Star
Western Thunderer
Do you want to bet on that?
There was method behind the GWR way of doing things... with the asymmetric nature of the GWR key the ganger could tell immediately, by the way the key would lay in the hand, which way to place the key.
eastsidepilot
Western Thunderer
In colour terms balsa isn't too far from fir either - a slight reddening and darkening.
Dave also forgot to mention the scale keying hammer...
Yeah
you'll need that after a days running session, going round tightening all the keys upATB, Col...........I'll need a few thous'd of them chairs Dave
Dog Star
Western Thunderer
What with sorting of those LH and RH bits and pieces, you will need a hammer to keep the musical chairs in key!
Buckjumper
Flying Squad
Interesting bolt heads Dave, but they used spikes and trenails.
