Guest Jack Benson Posted June 18, 2019 Share Posted June 18, 2019 Hi, Bachmann's BR Std 5mt 73930 32-503 has an additional note - Westinghouse Pump What is the significance of this feature, were some members of the class fitted with a Westinghouse Pump for special duties? Some background information would be appreciated. Cheers Jack Link to post Share on other sites More sharing options...
Fat Controller Posted June 18, 2019 Share Posted June 18, 2019 A previous thread on this:- https://www.rmweb.co.uk/community/index.php?/topic/97653-westinghouse-brakes-when-and-where/ Link to post Share on other sites More sharing options...
Guest Jack Benson Posted June 18, 2019 Share Posted June 18, 2019 OK, thanks, that answers the use of the Westinghouse brake vs vacuum systems, however, why did BR Std 5mt 73030 need to be fitted? Presumably it allocated to duties which required to use of dual systems but where and what were the duties? I can understand the need for additional air pumps on special duties for 9Fs on Consett hopper trains but this 5mt was more passenger traffic than heavy goods, I am baffled..... Cheers Jack Link to post Share on other sites More sharing options...
Bernard Lamb Posted June 18, 2019 Share Posted June 18, 2019 73030 and 73031 were fitted with Westinghouse brakes from new in June-July 1953 for trials with fitted freight trains. two Britannias 70043 and 70044 also took part in these trials. The equipment was removed after these trials and after some time at the Rugby test plant. Taken from the book on BR Standards by Richard Derry. I hope that answers your question. Bernard. 1 1 Link to post Share on other sites More sharing options...
RMweb Gold Oldddudders Posted June 18, 2019 RMweb Gold Share Posted June 18, 2019 73030 and 73031 were built new with pumps on the offside by the smokebox. They, and some Brits, were trialled with freight wagons, mainly coal opens, also converted, obviously. But the logistical problems of ensuring only air-braked wagons were paired with the locos, and the implications for a nationwide fleet of hundreds of thousands of such vehicles, made it seem unworkable. The pumps were removed soon thereafter. Beaten to it by Bernard! 1 Link to post Share on other sites More sharing options...
Fat Controller Posted June 18, 2019 Share Posted June 18, 2019 25 minutes ago, Jack Benson said: OK, thanks, that answers the use of the Westinghouse brake vs vacuum systems, however, why did 2 minutes ago, Oldddudders said: 73030 and 73031 were built new with pumps on the offside by the smokebox. They, and some Brits, were trialled with freight wagons, mainly coal opens, also converted, obviously. But the logistical problems of ensuring only air-braked wagons were paired with the locos, and the implications for a nationwide fleet of hundreds of thousands of such vehicles, made it seem unworkable. The pumps were removed soon thereafter. Beaten to it by Bernard! 2 minutes ago, Oldddudders said: 73030 and 73031 were built new with pumps on the offside by the smokebox. They, and some Brits, were trialled with freight wagons, mainly coal opens, also converted, obviously. But the logistical problems of ensuring only air-braked wagons were paired with the locos, and the implications for a nationwide fleet of hundreds of thousands of such vehicles, made it seem unworkable. The pumps were removed soon thereafter. Beaten to it by Bernard! need to be fitted? Presumably it allocated to duties which required to use of dual systems but where and what were the duties? I can understand the need for additional air pumps on special duties for 9Fs on Consett hopper trains but this 5mt was more passenger traffic than heavy goods, I am baffled..... Cheers Jack I believe there were a hundred 16t mineral wagons built with LMS-designed 8-shoe brake-gear for these trials; they were later converted to vac-brakes. BR seemed to go through fits of wanting to trial air-brakes; does anyone else remember photos, in Modern Railways, of an EE Type 3 hauling a very long train of air-braked Ferry Vans through the Peak District? 1 Link to post Share on other sites More sharing options...
Guest Jack Benson Posted June 18, 2019 Share Posted June 18, 2019 Ian, Bernard, Brian, Thanks for the explanations, they bring clarity to the puzzle. Cheers Jack Link to post Share on other sites More sharing options...
RMweb Gold The Johnster Posted June 18, 2019 RMweb Gold Share Posted June 18, 2019 As it was explained to me back in the 70s when I worked on the railway, vacuum brakes were generally used with steam locos because they were easy to 'blow off', release, with the large ejector on the loco. Westinghouse air pumps were less powerful, but more suited to electric stock and the 'chunka chunka chunka' sound of the electrically driven pumps would be familiar to anyone old enough to remember red London Underground or green Southern Electric trains. Diesel and electric traction is more suited to air brakes blown off by compressors. Train air and vacuum brakes are separate from locomotive steam or 'straight air' brakes. Train brakes are required to be 'fail safe', and are held off the wheel by vacuum or air pressure, applying by weight or spring when pressure is lost, but loco steam or straight air brakes are pressured on, and release if pressure is lost. A 'dual fitted' loco thus has 3 separate braking systems, the steam or straight air which works only on the loco's wheels and a vacuum and an air brake that works on the train's wheels. On a part fitted freight train there is of course a fourth, the guard's brake in the van, and on a loco there is also a handbrake; not uncommon in accident reports to read that all available brakes had been applied fully in desperation, or none if the situation had developed too quickly for the crew to react. When train air brakes were widely adopted on BR from the 1960s onwards, a 'dual pipe' system was used with a train brake pipe to operate the brake and a reservoir pipe to release it quickly when you needed to get on the move again, as the locos' compressors were rarely powerful enough to do this. So, a lot of pipework appeared on the buffer beams, and things got a bit crowded when steam heating bags, control, and electrical cables were included in the mix as well. Dmus had a dual pipe vacuum system that worked in much the same way, with a brake pipe and a release pipe; this was very effective and even on a 12 car train the brakes could be released instantaneously. All braking systems that rely on flexible hoses (bags) leak, and pressure must constantly be maintained. Link to post Share on other sites More sharing options...
Londontram Posted June 18, 2019 Share Posted June 18, 2019 7 hours ago, The Johnster said: vacuum brakes were generally used with steam locos because they were easy to 'blow off', release, with the large ejector on the loco. Westinghouse air pumps were less powerful, but more suited to electric stock The Caledonian railway seemed to get on ok with it for the best part of 40 years. I don't recall any mention of their brakes being less effective than any other railway company. 1 Link to post Share on other sites More sharing options...
RMweb Premium 31A Posted June 18, 2019 RMweb Premium Share Posted June 18, 2019 The Great Eastern likewise, on the intensive Liv. St. Jazz trains! Link to post Share on other sites More sharing options...
RMweb Gold The Johnster Posted June 18, 2019 RMweb Gold Share Posted June 18, 2019 (edited) As did the Rhymney, and the Great Eastern, and IIRC the G&SW and the LT&S as well. The GW thought it was better than everybody else and in some ways it was; it's vacuum brakes worked on the loco and tender wheels as well. It then let itself down by insisting on 23 inches of vacuum as opposed to everyone else's 21 inches which were perfectly adequate for the task, meaning that any vacuum fitted train that changed locos from a GW type to anyone else's had to have every cylinder on the train isolated (by hand, you pull a cord (position marked by a white star on the solebar) which equalises atmospheric pressure on both sides of the vacuum cylinder, which then drops under it's own weight and releases the brakes) while a handbrake held them, and then had to be 'recharged' by the new loco, a time consuming job that was real fun for the guard with a 60 wagon fitted freight on a dirty night... Isolating the brakes also had to be done when the train had to be shunted, as this is done with the handbrakes to save time. Any movement with passengers aboard must be done with the automatic brakes tested and working, though. At least air brakes were a Westinghouse standard. I suspect a steam loco probably could release vacuum brakes quicker than air, but there wasn't much in it! Diesels and electrics which had to use a compressor for this job were much quicker with air brakes, one of the reasons for it's widespread adoption after steam was dispensed with; some of them struggled with long vacuum trains. Edited June 18, 2019 by The Johnster Link to post Share on other sites More sharing options...
Steamport Southport Posted June 19, 2019 Share Posted June 19, 2019 I thought most fitted CR locos were dual fitted? The carriages were. They spent much of their time working with other companies stock and vice versa particularly LNWR. Jason Link to post Share on other sites More sharing options...
pH Posted June 19, 2019 Share Posted June 19, 2019 3 hours ago, The Johnster said: As did the Rhymney, and the Great Eastern, and IIRC the G&SW and the LT&S as well. The G&SWR changed from Westinghouse to vacuum in the mid 1880s. 1 Link to post Share on other sites More sharing options...
Guest Jack Benson Posted June 20, 2019 Share Posted June 20, 2019 Hi, Having drifted away from the subject of the Bachmann 32-503 73030, the model has pitched up. Nice runner but baffled by the presence of four 2,5mm holes spaced either side of the top of the boiler, please, no guesses as I am about to cry foul and ask for a refund. A manufacturing feature by Bachmann or were the top of the 5mt boilers pierced by fairly large holes, if so, why? Never rains but it pours Jack Link to post Share on other sites More sharing options...
Bernard Lamb Posted June 20, 2019 Share Posted June 20, 2019 18 minutes ago, Jack Benson said: Hi, Having drifted away from the subject of the Bachmann 32-503 73030, the model has pitched up. Nice runner but baffled by the presence of four 2,5mm holes spaced either side of the top of the boiler, please, no guesses as I am about to cry foul and ask for a refund. A manufacturing feature by Bachmann or were the top of the 5mt boilers pierced by fairly large holes, if so, why? Never rains but it pours Jack I don't have a drawing nor any photos with a view from above. Not a clue what the holes are for but the Bachmann model has them. It is not an aberration on your particular model. Bernard Link to post Share on other sites More sharing options...
RMweb Gold PhilH Posted June 20, 2019 RMweb Gold Share Posted June 20, 2019 (edited) As can be seen from this wikipedia photo they are there on the prototype. As always Google is your friend. Edited June 20, 2019 by PhilH 1 1 Link to post Share on other sites More sharing options...
Guest Jack Benson Posted June 20, 2019 Share Posted June 20, 2019 Hi Phil and Bernard, Thanks, at least it isn't a fault and no need to return. Cheers Jack Link to post Share on other sites More sharing options...
peterfgf Posted June 21, 2019 Share Posted June 21, 2019 13 hours ago, PhilH said: As can be seen from this wikipedia photo they are there on the prototype. As always Google is your friend. The two "holes" visible on the top in the boiler cladding may be wash-out plugs (compare their size to the five plugs visible on the side of the firebox below the handrail). Probably quite useful for removing sludge from the bottom the boiler barrel. I've just had a look at the RCTS book on the class 5 standards but there I can't find a mention of these fittings. Peterfgf Link to post Share on other sites More sharing options...
Steamport Southport Posted June 21, 2019 Share Posted June 21, 2019 Yes. Washout plugs. It's just that they look a bit deep on the Bachmann model. Possibly not helped if you are looking at them from above. Jason Link to post Share on other sites More sharing options...
Bernard Lamb Posted June 22, 2019 Share Posted June 22, 2019 Curiosity led me to look at a few photographs. I find that the 76XXX also has these holes. Both on the real thing and the model However on the Bachmann model they are not as deep as on the 73XXX. Bernard Link to post Share on other sites More sharing options...
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