With such a setting, when the exhaust opens, the steam in the cylinder is near full boiler pressure.

The boiler pressure had therefore to be reduced from 16 to 14 bar, which meant the locomotives lost a considerable amount of power.

The corrugations also provided additional strength to resist boiler pressure.

The boiler working pressure was 235-240 pounds per square inch.

Gilbenstock brought the boiler pressure down after a few minutes, seeing no need for further tests.

From the second series, built in 1904, the boiler pressure of the S 3/5 was raised from 14 to 16 bar.

As a result the initial boiler pressure of 25 bar was quickly reduced to 16 bar.

All were reboilered during their lives to raise the boiler pressure from 130 to 160 pounds per square inch.

Tractive effort was calculated at 15,330lbs with a working boiler pressure of 200psi.

Operating as a compound at a boiler pressure of 350 psi it covered over 100,000 successful miles.