Sheff's Recent Activity
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Sheff liked Allegheny's post in the thread GWR four-cylinder arrangement?.
Electrical equipment has a "Continuous Maximum Rating" (CMR) which, as the name implies, is the maximum output it can produce continuously before its life is shortened by excessive temperature. For short periods the output can be much higher, in...
Jul 13, 2026 at 10:07 AM -
Sheff liked LMS2968's post in the thread GWR four-cylinder arrangement?.
Yes it can, but there are still limits as to the power which can be generated and then delivered; diesels (and electrics) do not have super powers when it comes to climbing gradients. There are still limits. There are advantages and...
Jul 13, 2026 at 7:58 AM -
Sheff liked twr12's post in the thread RTC: Eddystone to York - 11/07/26.
What has to be remembered, when moaning about the diesel doing most of the work, that the cross section of passengers on the train means that there is practically no option to cancel the train when Network Rail impose Red restrictions to steam...
Jul 12, 2026 at 5:36 PM -
Sheff liked ghost's post in the thread New build M&GN C class.
Neither project would be mentioned here as this is a thread for a specific standard gauge loco. Gowrie is mentioned in several of the FR threads. The ZA6 has its own thread which was updated in March 2026. If you have updates, feel free to...
Jul 12, 2026 at 5:35 PM -
Sheff liked Jamessquared's post in the thread GWR four-cylinder arrangement?.
So just imagine the logistics for a while. In the normal scenario, a loaded rain comes to rest at Tebay (for Shap). The banker runs onto the back from a convenient siding; within a few minutes the train is back on its way. The banker drops off...
Jul 11, 2026 at 8:30 PM -
Sheff replied to the thread GWR four-cylinder arrangement?.
But was only for short bursts up the bank, with time between turns to clean the fire and box it up again .
Jul 11, 2026 at 7:07 PM -
Sheff liked Steve's post in the thread GWR four-cylinder arrangement?.
Unburnt coal going up the chimney; plain and simple. You need to define what you mean by char but, in my book it is unburnt coal or, more exactly, partially burnt coal which has lost its volatile content but still contains unburnt carbon. That’s...
Jul 11, 2026 at 7:05 PM -
Sheff liked Jamessquared's post in the thread GWR four-cylinder arrangement?.
And the overall financial efficiency of that? You are falling into the same trap as everyone else, finding ever more elaborate workarounds to enable one technological option while ignoring the total cost of operation. Tom
Jul 11, 2026 at 11:52 AM -
Sheff liked Jamessquared's post in the thread GWR four-cylinder arrangement?.
It's not the steam to power the stoker that is the issue, it is that large amount of coal disappears straight up the chimney unburnt. Tom
Jul 11, 2026 at 11:51 AM -
Sheff replied to the thread GWR four-cylinder arrangement?.
I would say that the unburnt fuel loss was more due the amount of fines that were generated by the screw feed system, which simply passed straight through the tubes and out of the exhaust without ever properly combusting. Take a look at the...
Jul 11, 2026 at 9:55 AM -
Sheff liked Jamessquared's post in the thread GWR four-cylinder arrangement?.
Sorry, I don’t understand that? Are you saying that fitting a mechanical stoker has neglible impact on efficiency? Because my understanding was that typically you’d burn about 25% more coal for the same output. Which rather screws your overall...
Jul 11, 2026 at 9:49 AM -
Sheff liked Jamessquared's post in the thread GWR four-cylinder arrangement?.
How do you propose to fire a 6,000hp steam loco? That’s well beyond the capability of a single fireman, so you fall back presumably on a mechanical stoker - which rather throws away the enhanced cylinder efficiency by creating worse boiler...
Jul 11, 2026 at 9:49 AM
