GWR Lubrication: 6695 etc.

My memory of them in service is that a lot of them had various modifications and 'experiments' carried out. These were indicated by a rectangular brass plate attatched to the frame above the cab steps giving the details. They were placed there so as to be in the driver's eye line as he mounted the loco.

Meic

 

I believe modifications to remove crown feeds were instigated on many of the classes but Swindon didn't get around to completing the job or maybe, as Gwenllian says, some were experiments to see how individual engines responded. In other words the removal appears somewhat random. With regards the 56/66xx class some members of the class were modified, 6697 is the only surviving example of felt pads/no crown feeds as far as I know of the engines which have so far been steamed. I don't believe anyone has converted a 56xx back to crown feeds. Neither do I know if any of the unrestored examples are felt pad/no crown feed.

 

At the beginning of this thread I commented that I thought BR(W) began the fitting of mechanical lubricators to the GW 4-6-0's, however it appears I was wrong. I recently had cause to re-read parts of my copy of Peter Skellon's excellent book on steam loco lubrication (looking for some guidance on a different lubrication issue) and came across mention of the fitting of mechanical lubricators to these engines.

Swindon experienced problems with lubrication of the Hall's fitted with new streamlined passages in the cylinder blocks with reports of excessive/undue wear. Apparently the atomised oil from the standard GW sight feed lubricators did not adhere to the new streamlined passages and went straight to exhaust, there were also thoughts that incorrect/erratic feed rates (down to the driver) were not helping either. Swindon began experimenting with mechanical lubricators on some Hall's in 1946, and this continued into the BR era with more of the 4-6-0 classes being progressively fitted. The mechanical lubricator gave a constant feed rate and the atomisers (subsequently fitted after problems with check valves disintegrating) did not atomise the oil to such a high degree as the sight feed lubricator.

So Orion, Swindon did (in this instance) acknowledge the benefits of mechanical lubrication for regulator, steam chests and cylinders.

 

Mechanical lubricators to the cylinders/valves were tried out around about 1905 on early Saints, before the standard arrangement was, well, standardised. I think there was the odd experiment carried out in the 20's & 30's as well. Castle's from 7000 onwards (1946) also came out with them.