Quote:
Originally Posted by YM-Mundrabilla
As an old Railwayman Landlubber can I ask a couple of (perhaps stupid) questions, of some of the engineers on SH, please?
Assuming a reciprocating steam engineroom:
How are the various speeds 'full', 'half' and 'slow' etc defined? Is it by RPM which presumably (?) gives a more or less set speed?
Am I correct in understanding that marine reciprocating steam engines do not have 'cut off' on the valve gear (as in a locomotive) but only ahead/astern? On this assumption is engine speed controlled only by the boiler steam throttle/regulator valve?
Again assuming, on the basis that there is no valve cut off, the lost efficiency is more or less made up by compounding?
I have some steam locomotive knowledge but know little (nothing actually!) about marine steam. 
Geoff (YM)    |
My one & only short steam triple expansion recip experience was v nearly 60 years ago but my memory is running with stop valve full open and controlling speed with boiler pressure and shut-off on the reversing gear. Did I dream that and fail my Chief's ticket?!