Endangered species Having had a good couple of days the Barrow Hill gala on the Thursday and Friday I headed off to the Midland Railway Centre at Butterley in Derbyshire hunting endangered big game! I was after the unique, sole surviving Caprotti valve geared Standard Five 4-6-0 no 73129 in action before its boiler ticket expired and it was withdrawn from service, The Locomotive was part of the last batch of thirty steam locomotives built at Derby Works in 1956. This engine was a long term restoration from being purchased from Barry Scrap yard in 1972 and it was stored outside cosmetically restored for a long time Restoration did not start in earnest until 1993 and it was 2005 before it entered full traffic on the line more soon
The weather on Saturday was beautiful and the distinctive sharp beat of the poppet valves could be heard echoing around even if the loco was not being worked particularly hard The video shows the loco working at Butterley and Swanwick with some close ups of the rotary valve gear in action cheers Kev
Interesting valve gear arrangement. I was completely unaware such existed. Did it work well in those days of it;s regular service? Was it difficult to maintain?
we are looking at £80,000 for the boiler work so some serious fund raising required. The 7F 2-8-0 is coming back together to take over the bulk of the running for the forseeable future. The Caprotti valve gear was first tried on the Italian state railways back in 1921 and was used on various types of British locos culminating in the last Hurrah of British Steam 'Duke of Gloucester' Because most of it is enclosed it was much more durable and efficient and the exhaust sounds wonderful even at small throttle openings
The caprotti valve gear improved the efficiency of the steam engine, and reduced the complexity, weight and resistance of the standard distribution gears (eg the Walschaerts), howewer the caprottis were more expensive to build and maintain, so even in Italy (we had quite a few of them, some hundreds) were the first in the scrapping list when the electrics took the bulk of traffic, together with mosf of the Franco-crosti pre heaters. Their superior performance was not the first priority for branch line service, alas. Here the wiki link https://en.wikipedia.org/wiki/Caprotti_valve_gear ciao
Was always interesting to watch a Caprotti fitted engine moving slowly past and watch the rotary gear working. Made a change from the usual Walschaerts.
Hi Kev, Good to see another UK modeller and Full size railway supporter on here! As a young one I remember watching these in the Leeds area and asking why they were different..... Whilst my father was knowledgeable about railways he had cut off his area of expertise once3 BR began! Ask him more or less anything about even a minor Scottish railway companies engines and he knew the answer. I was away at school and looked it up in the library when I was 11 to find out the difference. Thanks
Kev, I don't know how I missed this when you first published it. Had never seen Caprotti valve gear in action, and thank you for showing us. She certainly has a sharp exhaust when working, and is very "square" as we Yanks are prone to refer to equal timing among all four exhaust "chugs."
