Todays project was a Loading Gauge. The one I made for St Ruth is of a later design with a post from 2 lengths of bull head rail bolted (or rather soldered) together, but for Modbury's early period I felt that a timber post version would be much more appropriate. There is a photo of quite a nice one at Malmesbury in Stephen Williams' Great Western Branch Line Modelling (Part 2), and it was this that I based my model on. Having no actual drawing of a timber loading gauge, I used a drawing of a rail built example to get the basic measurements and scaled the Malmesbury photo on the known dimensions of 9'8" across the width of the gauge, and 13'6" from rail head to underside of the gauge.
A somewhat cruel close up of the finished loading gauge after painting - the whole thing is only 40mm tall!
My model started out as an aborted signal post (I'd milled the taper at too steep an angle). The taper of the post was corrected by careful filing, an oversized piece of 0.010" etch was soldered onto the top of the post then filed back until it was just proud of the post all the way round, and then the post cap was filed to have a slight taper from middle to edges. The cross bar would appear to be about 3'0" from the top of the post, so a length of 1mm square brass bar was prepared for the cross bar with a small piece of the same material soldered along the side at one end. This extra bit was attacked with needle files to produce the ornamental strengthening piece evident where the cross bar buts up to the main post, and once I was happy the cross bar and main post were soldered together 6mm down the post. The main post itself also has a carved wider section at the door of the post, so a bit of 0.028" nickel silver was sweated onto the side of the post an it too was attacked with needle files until I was happy with its shape and size.
A 0.3mm hole was drilled at a slight angle near the top of the post for the straining wire, and a pair of holes drilled in the cross bar for the same straining wire (the hole nearest the post being where the straining wire enters the cross bar and a hole a mm or two further out for the bit of the wire that appears on the far side of the cross bar with the nut on it. A length of wire was soldered in place to represent the straining wire then cut back to size. Further 0.3mm holes were drilled through the cross bar for the chains that the gauge was suspended from.
The actual gauge itself was carefully bent up from a length of 0.6mm wide nickel silver strip - on the last etch I had done I filled up an odd space in the artwork with a sub-etch of 0.5 and 0.6mm wide strips as I thought they might be useful one day! The chains were made in the same way that I make handrail knobs for my locomotives, a loop of thin wire (very thin in the case of these suspension chains) has the two tails trapped in a pin vice, the loop passed over a drill in another pin vice , and the pin vice with the loop in spun until a tight twist of wire is formed with an "eye" around the drill. The eye was slipped off the drill, and passed over the bent up gauge and another made - rather surprisingly I only needed to make the two as I didn't lose any! The suspension chains were tack soldered to the gauge and the ends of the chains threaded through their holes in the cross bar before being secured in place with another quick in and out with a soldering iron.
The various solder joints were carefully cleaned up (especially around the various bits of wire), and finally the securing metal strap added (from 0.005" plasticard) where the cross bar meets the main post. A coat of white primer, a touch of Precision Paints Dirty Black around the foot of the post and then various washes of much thinned Dirty Black completed the loading gauge.
Tomorrows task will be to site it on the layout, it is intended that the loading gauge will go on the goods loop, and be used as a marker for the uncoupling electro magnet.
Thanks for looking.
Ian
