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:

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.