About 40 mph was ideal, performance fell off under that, but also over that as you got a "bow wave" ahead of the scoop, less water loaded and more spillage. Photographs of expresses at speed with substantial spillage coming from the scoop area under the tender show this. There was a further problem that at higher speeds it could be difficult for the fireman to raise the scoop when the tender tank got full due to water pressure against the scoop, whereupon all sorts of problems could arise as water suddenly started discharging from the overflow pipes on the tender - leading coach soaked (remember open window ventilators), coal washed from tender top, which might break the windows of the leading coach, etc. The way round this was not to dip the scoop too much at higher speeds, but then you didn't get a good fill, so if things were looking empty a drop in speed would help. Troughs also gave problems for the second engine of a double header. Now we rarely double headed on the Western of course
but on the WCML it must have been an issue.... Troughs also gave problems for the second engine of a double header. Now we rarely double headed on the Western of course
The only heated water troughs I've read about were those just south of Garsdale/Hawes Junction station on the Settle and Carlisle line.
Only a few US roads had them - New York Central was the principal one. The NYC also had mid-route coaling plants, but these were at stations rather than picked up on the move! In the US it was long the standard that 100 miles = one day's pay for crews, and points for crew changes were placed accordingly. There were few runs like Kings Cross to Edinburgh nonstop.
Railways always tried to have level sections of track unless compelled otherwise by the lie of the land, since gradients mean more work by the loco and therefore greater running costs. Early lines were probably not specifically designed for troughs, as these were developed by Ramsbottom of the LNWR only in 1860. After that, further lines probably were designed by the civil engineer to include level stretches at appropriate intervals so that troughs could be installed with minimum effort.
I recall a statement by the presumably knowledgeable staff of the Railway Magazine, in a question-and-answer exchange in that periodical some time in the 1950s: that there had only ever been a little incidence of water troughs on the European Continent -- one of the few exceptions being on France's Ouest-Etat system. Continental railways' reasons for on the whole rejecting water troughs, are indeed surmise on my part -- prompted by neilmc's thought that the device can be seen as "another thing potentially to go wrong". One would imagine that Western Europe's bigger and more highly-developed nations would at least have considered adopting the idea; but, one guesses, decided in the end, "more trouble than worth" -- plus, as you suggest, maybe an element of "sour grapes" vis-a-vis the perfidious Brits.
One muses -- celebrated German efficiency possibly tackling the issue in another way? -- given the motivation, one would imagine that water-column use / loco changing, could be made pretty snappy.
The GW troughs, and certainly the ones at Creech outside Taunton, seem to have been commonly where the railway paralleled a river/canal (as there), or coastline, where the line will have been naturally level. There are plenty of other level sections, when the lines were first laid out engineers seem to have found it easier to have level sections interposed with sections of a standard gradient, rather than extremely gradual inclines of 1 in 1000 or less, which were probably beyond the surveying instruments ("just get the bubble in the middle") or manual labour of the time.
