Spoked wheels on A60stock and other stock?

Q Stock had spoked wheels a feature which many modellers including me have fitted to the models we have made

XF

d7666 is correct.

Spoked wheels are far less prone to stresses and metal fatigue (thus failure) than solid. Even in the days of "wheel tappers", failures still happened, but now only a computer can spot stress fissures.

Bombardier?

Didn't T stock have spoked wheels too?

Doing my 67TS research, I came up with the following:

A new feature of the ’67 Stock was the adoption of one-piece “monobloc” wheels on the motored axles instead of the traditional, tyred wheels. This was said, at the time, to be possible because they expected a reduction in wear on motored wheels with rheostatic braking being used in place of friction braking. They also expected improvements in tyre condition because of the better cooling properties of solid wheels.

Thinking about it, I originally assumed that spoked wheels were retained on motored axles because the weight on the wheels was higher than on non-motored wheels and that this would lead to greater wear on tyres and they would therefore have to be re-profiled or replaced more often. Trailer wheels would need tyre changing so often, so making them monobloc would be cost effective. This then led me to wondering when it was that monobloc wheels first appeared and whether it was sensible to have two types of wheel on the same train, or even the same bogie. I did a bit of digging.

Traditionally, wheels consisted of two parts; the wheel itself (usually spoked) and its tyre – the bit that actually sits on the rail. When the tread of a tyre wore out of shape, the wheelset had to be removed and sent, on the Underground anyway, to Acton Works for “re-profiling” on a large lathe. The average tyre would usually last four such “turnings” before it got too thin. It would then have to be replaced. The old tyre was cut off and a new one shrunk on. This was done by heating the tyre on a special heater on the shop floor and then lowering the wheelset into the tyre and letting it cool to give a tight fit. It was secured with a retaining ring. There were various designs of these and railways tended to develop their own preferences.

Naturally, all this work was expensive and ways were sought of reducing the costs. One solution was the solid, (forged or cast steel) monobloc wheel. One might be forgiven for thinking that the use of monobloc wheels was a new idea in the 1960s but, as I discovered in my research, they had already been around a long time. I haven’t been able to find out exactly when they were first introduced but one is listed, with a photo, a US publication of 1911 . The idea seems to have been more popular in North America than here, largely because the heavier axle loads there led to high tyre temperatures being generated during braking. Temperatures of over 1000 deg. C could be recorded in spots and it isn’t difficult to imagine what this would do to a steel tyre. Heating could be so severe that tyres would expand and then shift on the wheel . In extreme cases, the tyre would come off the wheel and derail the train. Problems of this sort drove American railroads to adopt solid wheels and, by the late 1950s, they were almost universal on their freight cars.
British railways, on the other hand, were very conservative and didn’t take to change easily. The perceived wisdom of the time was that a wheel with a separate tyre was less expensive than a solid wheel. With a tyred wheel, all you had to do was replace the tyre, not the whole wheel. However, two-piece wheels needed more facilities than solid wheels; equipment was needed for removing the worn tyres, machining the wheel rim and fitting and turning the new tyres, whereas solid wheels only require returning. At the end of its useful life, however, the solid wheel has to be pressed off its axle and the wheel seat may have to be skimmed up before another wheel is pressed on.

The economic balance between the two types was in the wear rate and the associated frequency of turnings. It also gradually became clear from experiments conducted in Sweden in the late 1950s that one-piece wheels had better cooling properties than spoked wheels . This would be a popular feature for a system like the Underground, where there was frequent heavy braking and therefore high heating and cooling cycles. Better cooling means less tread damage and less internal stresses .

The Underground seems to have started using solid wheels on tube car trailer axles in the late 1930s. As far as I can find out, the 1938 Tube Stock was the first to have them fitted in bulk. Solid wheels were confined to trailer axles because, as I mentioned above, of the additional weight and thus wear, on motored axles.