71000

No, each side drives both admission and exhaust valves on that side. The middle valves are driven by a cross shaft from one of the outer camshaft drives, but I can't remember which one.

 

Beaten to it

 

I'm not sure whether you're commenting on @LMS2968's first or second sentence. If the first, then yes. Most valve gears, including Walschaerts and Stephenson's, drive slide or piston valves that control both admission and exhaust. But if the second sentence, then no. Most three cylinder locos (at least in Britain) have either three sets of Walschaerts gear or two sets of Walschaerts gear with Gresley derived motion for the middle cylinder.

 

Thanks for that, thankfully Sentinels are a bit simpler.

 

For completeness I should add that three cylinder locomotives on the NER (including the preserved Q7) had three sets of Stephenson valve gear, all inside which made the crank axle very congested with the crank and six eccentrics.

 

Having oiled 63460 up in my earlier years, I’m pretty certain I couldn’t do it now! Mind you, the NER obviously didn’t expect their footplate crews to be anything other than super slim. Anyone who has tried to mount the footplate of a Q6 or J27 on a curve will know it’s so much easier on the outside of the curve and virtually impossible for any one of modest proportions on the inside of the curve.

 

Did the long wheelbase of 18feet and a half prohibit it somewhere on NYMR?

 

No prohibitions on running lines. It may have been prohibited in the now gone beck siding at Pickering station. Several locos were prohibited in there. A long time ago now an I can’t remember. The NYMR didn’t run into Whitby then.