Starting a WR Diesel Hydraulic

On the WSR thread it was mentioned that the DEPG provides a 'cold start' diesel loco - usually a 33 for Thunderbird Duties at Minehead. The Diesel Hydraulics cant be used for this as they are not 'cold start'

So how do you start them? Also it seems to me that if you cant just get in & 'turn a key' then that brings with it a lot of inflexibility that in BR days may have been another reason to get rid of them

 

They are fitted with pre-heaters, so need a time to pre-heat before being started. I read D1062 was used as a Thunderbird on the SVR this summer, luckily it had been pre-heated for other reasons or it would not have been available.

Patrick

 

Martin Walker has fitted a pre-heat system to 55022, together with gas heat and analysis system, to warn of any problems.

 

How are they pre heated and how long does pre heating take?

 

Its either an electric blanket, or coolant water is heated, will have a check, and come back.

 

from
http://www.westernchampion.co.uk/loco-d1015-technical.php

Why do we preheat engines?

In order to aid starting a Maybach diesel engine the coolant water is warmed to 110°F (around 43°C). This warms the cylinder heads and helps combustion of the diesel fuel oil. The combustion of the fuel and air mixture takes place inside a chamber within the cylinder head and then expands into the cylinder itself, forcing the piston downwards. The characteristics of this engine type doesn't lend itself easily to cold starting. Warmed engines start more easily, should run cleaner with the added bonus of reduced wear and deposits (carbon etc) associated with cold starting of any diesel engine.

There are a number of unique advanced features incorporated in a Maybach MD series diesel engine such as pressure oil cooled two piece pistons, roller main bearing crank shaft, quadruple overhead camshafts, six valves per cylinder head (3 valves air inlet and 3 valve exhaust gases) and a individual pump / injector unit per cylinder.

The engine coolant is warmed by a small preheater, located in a compartment behind the cab side doors at each end. The preheater only runs prior to starting or when the engines are shut down and are getting 'cold'. You can hear them running sometimes when we shut down the engines at stations. It carries out the same purpose as glow plugs do in modern diesel engine cars.

Although it is possible to 'cold-start' a Maybach engine it is not recommended.

 

Thank you for that

I once 'cold started' a Newbury 6cyl 'O' Type Sirron (1930's 2 stroke trunk piston marine engine) in March.

We used a lot of air and with the 'bangs' as the overpressure valves blew on all the cylinders so I can understand why you don't always want to cold start.............

 

you're thinking of clockwork I suspect

 

Curious to know if the pre-heat requirement was for all Diesel Hydraulics or just those with Maybach engines...??

For example, the Class 14's have Paxman engines, are they subject to pre-heat as well...??

 

It sounds like these engines are of the indirect injection type which I'm surprised was still the 'norm' for not only the time they were built, but also taking the size of the engine into consideration.

 

I look after a range of diesel generators ranging from between 350 kw up to 1.4 mega watt all use a coolant preheating system and all will start at a flick of a switch , I used to look after a diesel generator which was container mounted compressed air start which dated back to the second world war and I be leve was an old minesweeper diesel , engine and the only way to start it in winter was to pile old pallets up under its trailer mounted container and light a match !

 

i remember seeing an article in a TI or RM 1960 ish that mentioned a new (then) class of diesel that was electrically heated to 70C when not in use . possibly D1500 class

 

The D1500 class (later Class 47) were direct injection Sulzer engines and had no pre-heating equipment as far as I'm aware.

 

There's a difference between what's possible and what's best practice. The wear to any IC engines starting from cold is way more than occurs with everything (including lubricants) at working temperature.

 

lol ..... a Co. I used to work for ran a fleet of Bedford TFs . some would refuse to start on a cold morning so we would push the offender round the block with one that behaved , until it started . never saw this recommended in the workshop manuals . they stopped us using damp start after a couple of heads blew off

 

With the old Bedford I wrestled in my youth (a TK of indeterminate pedigree which ran on trade plates), the usual probem was a decidedly unenthusiastic decompression valve, which could cause embarrassment to the uninitiated. A sometime breakdown recovery flatback, I recall it's suspension was 'interesting' when loaded with LPG cylinders too.

 

And, of course, you never used the 'naughty stuff' that come in an aerosol container………..