Go Back   Shipping History > Shipping Discussion > Mess Deck > The Engine Room

Landlubber questions.

Post Reply
 
Thread Tools
  #1  
Old 29th March 2019, 11:56
YM-Mundrabilla's Avatar
YM-Mundrabilla Australia YM-Mundrabilla is online now
Senior Member
 
Join Date: Apr 2017
Location: Mundrabilla (haha), Melbourne really but I'd rather be in Narvik
Posts: 289
Images: 934
Landlubber questions.

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.

Any comments will be appreciated, please.

Regards
Geoff (YM)
Reply With Quote
  #2  
Old 29th March 2019, 16:01
Engine Serang Europe Engine Serang is offline
Senior Member
 
Join Date: May 2017
Location: Dublin,
Posts: 601
YM, its 40 years since I did my Chiefs and things are a bit hazy, will check.
Reply With Quote
  #3  
Old 30th March 2019, 06:27
Tom Alexander's Avatar
Tom Alexander Canada Tom Alexander is offline
Senior Member
 
Join Date: Apr 2017
Location: Nanaimo, B.C., Canada
Posts: 1,067
Images: 1
Quote:
Originally Posted by YM-Mundrabilla View Post
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.

Any comments will be appreciated, please.

Regards
Geoff (YM)
Being a "deckie" who never sailed with reciprocating steam (only turbines & Doxfods) could any one answering the thread also elucidate on what happened to the steam/engine when stopped or in astern ?????
Reply With Quote
  #4  
Old 30th March 2019, 12:45
YM-Mundrabilla's Avatar
YM-Mundrabilla Australia YM-Mundrabilla is online now
Senior Member
 
Join Date: Apr 2017
Location: Mundrabilla (haha), Melbourne really but I'd rather be in Narvik
Posts: 289
Images: 934
Chief ES and Deckie Tom.
To elaborate a little, my questions arose from a demonstration last Thursday 28/3 of a museum based two cylinder vertical steam engine, allegedly from a Murray River paddle steamer of the late 19th century, when the restorer repeatedly threw the valve gear (instantly) from 'full ahead to full astern'. I have to admit that the engine looked nothing like a PS engine to me but then I have no knowledge beyond the few Murray River paddlers having steam roller/traction engine machinery.
I always previously thought (still wonder) that this would not be good for the machinery and it was at this point when I asked about cutoff on marine reciprocating that the conversation became confused.
Regards and thanks.
Geoff (YM)

Last edited by YM-Mundrabilla; 30th March 2019 at 12:49.
Reply With Quote
Post Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Landlubber gray_marian Say Hello 18 24th May 2018 10:46


All times are GMT +1. The time now is 09:50.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.