71000

Well at one point I was lead to believe it was going Tuesday with 57003. But that’s now gone from a 5Z to 0Z path so maybe it’s just the 57.

 

BR testing was done in 1954. Test reports in general were more aimed at operating the locos within likely service parameters rather than establishing maxima. (the V2 test report was done in connection with its re-draughting at Swindon so they did want to see what it could do). That for 71000 is rather different from the others as it seems to have a greater focus on costs and optimal operating parameters (and to a limited extent, a comparison with diesel 10203). I doubt there were many, if any, BR services that required 30,000lbs/hr of steam and to generate this quantity is probably beyond the expected limit for one fireman. I suspect 71000 could produce more than this, 32,000lbs is mentioned although that is not enormous for such a large boiler. The report states that there was adequate air supply (indeed, a 30% excess) to burn the coal fully (the amount of air apparently being derived from an analysis of the exhaust gas quantities).

 

Fireside of flues and tubes are identical for BR standard 7 and 8.
Firebox surface area of BR 8 is 8% bigger and grate area 16% than BR 7.

Mr Giesl has made a formula for calculating max steaming as function of evaporating surface and grate area when burning a coal like Blidworth.
His method estimates max evaporation from BR7 to 29000 lbs per hour and 33500 for BR8

BR measurements according to Cox were 30000 for BR 7 and 29000 from BR 8 originally.
A reasonable estimate of Duke Max Steam in present oppened up state is thus 34500lbs per hour and 2800 indicated horsepower at most frugal point.

A Britania and a Clan with Caprottis will be nice to race again the Duke over Shap with train masses proporttional to empty mass of locomotives.

 

A Clan with Caprotti? I doubt we’ll ever see that, the new build has piston valves.

 

A question on your last para, what would be the point?

 

Investment in a steam locomotive depends on amount of metal used?
When my B16/4 is ready to prove that I am best locomotive engineer alive,it will be fair to strain locomotives with trains proportional to loco mass.

 

Good to see that you have your ego in check...

 

Some action from Saturdays test run




Sent from my iPhone using Tapatalk

 

To confirm 71000 leaves today being towed to Crewe by 57003

 

I'm struggling a bit with those figures and wonder how they were obtained. Stanier Pacific 6225 in 1955 and 1956, both on the rollers at Rugby and with the MTUs over the S&C gave a maximum output of 41,500lb/hr. This wasn't the boiler's maximum ability but the maximum the engine could use: above this slipping became uncontrollable and the engine - and boiler - had to be eased. The test crew decided on a nominal maximum output for the boiler at 42,000lb/hr.

In view of this, I wonder how a maximum of 48,000lb/hr was achieved from 71000, or 42,000lb/hr sustained for so long without the engine losing its feet?

 

Cox states that 46220 could produce max 36000 lbs per hour steady state and the Giesel model says 33500 if burning a Blidworth like fuel.

 

Less than ideal!

 

Did it leave the SVR with motion on?

Hope they haven’t had an epic en route.

Chris

 

Judging by the coupling rod sitting on the floor, I guess they have.

 

Scotch missed- didn’t spot that on a phone screen.

 

Leaving SVR…

https://x.com/railcamlive/status/1927334699107582361