Modernising Options

There are a wide range of “modernisation” modifications that can be applied to locomotives, both new and old. The following table offers a quick guide to modernising options that might be adopted and the benefits that they offer.

Readers’ attention is also drawn to two extracts copied from David Wardale’s book:

from page page 144 – Improving Locomotive Performance and Efficiency;
from page 145 – The Holistic Nature of Steam Locomotives.

The text and table below are taken from the 5AT website:

Modification	Benefits	Increase Performance	Reduce Fuel Consumption	Reduce Maintenance	Improve Reliability
Improved exhaust system	Reduce backpressure in cylinders to increase cylinder efficiency & power output, & reduce specific steam consumption (SSC)	√	√	√	√
Fit Kordina below blast pipe	Reduce back-pressure in exhaust passages to increase cylinder efficiency & power output, & reduce specific steam consumption (SSC)	√	√	√	√
Convert firebox to GPCS operation	Reduction of: unburned fuel carry-over; smoke & spark emissions & clinkering;	√	√		√
Increase superheat temperature	Increase thermal efficiency, thus reducing SSC, fuel consuption and carbon emissions.	√	√		√
Install feedwater heater(s)	Reduction in SSC & fuel consumption and/or increase in steam production.	√	√		√
Cover all hot surfaces with high quality insulation	Minimise heat losses and reduce condensation on cylinder walls.	√	√		√
Improved valve and piston lubrication	Reduce piston and valve ring wear and cracking of lubricant oils by applying them directly onto rubbing surfaces.			√	√
Multiple narrow valve and piston rings	Minimise steam leakage; reduced ring wear.	√	√	√	√
Multiple element piston and valve rod glands	Eliminate steam leakage from glands between overhauls	√	√	√	√
Modify valve ports and valve heads	Improve streamlining to reduce triangular losses & improve cooling of valve liners, valve heads and valve rings	√	√	√	√
Saturated steam cooling of valve liners	Reduce liner temperature – recommended for very high temperature superheat			√	√
Increase steamchest volume and steam pipe diameter	Reduce pressure drop of admission steam at high steam flow rates, improving efficiency and SSC.	√	√		√
Optimise valve events	Improve steam flow into and out of cylinders by adjusting valve motion, lap and/or lead.	√	√		√
Optimise clearance volume by modifying pistons and/or cylinder covers	Raise SSC, efficiency, etc by reducing incomplete expansion losses without impeding steam flow.	√	√		√
Fit roller bearings wherever practicable	Minimise wear, knocking and loss of valve motion.			√	√
Fit Franklin wedges to hornguides	Postpone development of knocking as hornguides wear			√	√
Fit Franklin-type buffing mechanism between engine and tender	Reduce buffing shocks between engine and tender; reduce fore-aft rocking from unbalanced reciprocating masses			√	√
Fit air-sanding equipment	Reduce risk of slipping and consequent delays, damage etc			√	√
Adopt mid-gear drifting	Maintain steam pressure against admisssion edge valve rings, and prevent smokebox contaminants from entering cylinders.			√	√
Adopt Porta water treatment	Reduces or eliminates corrosion and scale formation; dramatically reduces boiler maintenance costs.			√	√