Cylinder cocks

[Taunton]

This is an oddball question.

Cylinder cocks are small valves on the end of the cylinders, operable from the footplate, that can be opened to discharge condensed water etc. Now I am one of the lesser number here who recall BR steam days in some quantity, and not just on the WR. I really don't recall them being used, although I am sure they were briefly by the crews.

Move on to today, and with steam, especially on the main line with substantial trains, they now invariably appear to depart with the cocks opened and the front of the loco wreathed in steam from them, to the extent that you can't really see it, and I suspect the driver can't see the road immediately ahead too well either. And this is not just for a few seconds, they are kept open it seems until the train is well under way. It wasn't like this in old times.

Why has this practice started? Or why, in old times, was it not done?

 

[hexagon789]

This is an oddball question.

Cylinder cocks are small valves on the end of the cylinders, operable from the footplate, that can be opened to discharge condensed water etc. Now I am one of the lesser number here who recall BR steam days in some quantity, and not just on the WR. I really don't recall them being used, although I am sure they were briefly by the crews.

Move on to today, and with steam, especially on the main line with substantial trains, they now invariably appear to depart with the cocks opened and the front of the loco wreathed in steam from them, to the extent that you can't really see it, and I suspect the driver can't see the road immediately ahead too well either. And this is not just for a few seconds, they are kept open it seems until the train is well under way. It wasn't like this in old times.

Why has this practice started? Or why, in old times, was it not done?

I think this was mentioned in another thread a while back; drivers playing it extra safe.

 

[Cowley]

I think this was mentioned in another thread a while back; drivers playing it extra safe.

I assume to prevent any chance whatsoever of water carryover and hydraulicing?
It is an interesting point though. I don't remember steam (being too young), but whenever you see old footage of steam it does seem to have been driven differently.

 

[Flying Phil]

Could it also be that the majority of old footage had the locomotives in regular service and so short station stops with hot cylinders. Today the locomotives are not in such intensive service and so the cylinders cool down more often during the day?

 

[Cowley]

Could it also be that the majority of old footage had the locomotives in regular service and so short station stops with hot cylinders. Today the locomotives are not in such intensive service and so the cylinders cool down more often during the day?

That makes a lot of sense.

 

[furnessvale]

Could it also be that the majority of old footage had the locomotives in regular service and so short station stops with hot cylinders. Today the locomotives are not in such intensive service and so the cylinders cool down more often during the day?

I'll put a spanner in the works. A steam engine wreathed in steam looks good for the cameras!

I know a retired BR steam driver who scoffs when he sees this occurring.

 

[hexagon789]

I assume to prevent any chance whatsoever of water carryover and hydraulicing?
It is an interesting point though. I don't remember steam (being too young), but whenever you see old footage of steam it does seem to have been driven differently.

Exactly that, I suppose they play it safe because repair work is so expensive now.

Better to play it safe than play it very costly.

 

[Merthyr Imp]

I well remember in the shed area at Grantham in about 1961 seeing an A3 moving backwards with so much steam coming from the cylinder cocks that we spotters on the platform joked it was being jet-propelled!

 

[randyrippley]

could it be that the current generation of drivers simply don't have enough exposure / experience with specific locomotives to know just how far its safe to push them? Must be a big difference in skill set between driving a similar locomotive on a daily basis, and driving different locos each weekend

 

[jamieP]

could it be that the current generation of drivers simply don't have enough exposure / experience with specific locomotives to know just how far its safe to push them? Must be a big difference in skill set between driving a similar locomotive on a daily basis, and driving different locos each weekend

I think its more to do with how expensive it is to repair or replace cylinders if they get damaged so drivers are taught to be extra careful.

 

[billh]

Are there not high pressure spring controlled relief valves on the ends of cylinders, such that a rapid rise in pressure above boiler pressure due to the presence of water causes them to open in a safe manner without intervention from the driver? Perhaps these open on starting in combination with the manual controlled drain cocks?