"Modernisation Plan" Era Loco Maintenance

[kermit]

Hello all,

Didn't quite know whether to put this here or in "preservation", as you'll see......

I've noticed as I browse around the abundance of photos on the internet, it is often really easy to spot when a loco from the "Modernisation Plan" era is in service, or conversely stored, withdrawn, bought for preservation etc. It seems as though locomotives in service rarely exhibit any outward signs of rust (even though they may be 50 or more years old), but as soon as they are out of service, deep patches of rot and seam corrosion are evident, sometimes painted and patched over in varying shades.

How much effort has to go into keeping these old-timers ship-shape, and are many of them extremely crumbly just under the surface?

 

[ash39]

It's a good question and something I've wondered before too. Why does being exposed to the elements but 'in service' make any difference to the rate of corrosion?

Best theories I can think of;

1) Cleaning agents used on trains contains some kind of protective wax.
2) Not moving often allows water to collect in places that would normally empty with movement.

 

[DXMachina]

I'm guessing that a 12 or 16 cylinder diesel engine inside a UK loading-gauge body probably makes significant heat, enough to dry the locomotive out from within, and as soon as they are stored through a damp season, moisture within starts to take hold. I bet the insides dont get anti-rust wax but rely on regular drying.

 

[DownSouth]

I'll add another theory:

3) Oily grime picked up in normal operations gets into the vulnerable cracks and corners where the paint coat is useless and forms barrier protection, and even if it is removed in a deep clean (as opposed to a normal wash between jobs) it is quickly replaced in regular service.

 

[kermit]

Thanks everyone, some good ideas there, and reassurance that the phenomenon I had observed seems to have been noticed by others.

The "heat" theory would be less applicable to electrics of course - and this reminded me of the state that the preserved Merseyrail class 502 has been in at some points in its life

http://www.class502.org.uk/history/history-2.php

.....so when her sister units were still in service, was there terrible corrosion lurking just under the surface?

 

[Murph]

The "heat" theory would be less applicable to electrics of course - and this reminded me of the state that the preserved Merseyrail class 502 has been in at some points in its life

An electric loco in daily use should be generating quite significant heat internally, likely enough to dry it out relative to one that's sitting out of service for a prolonged period. Transformers, blowers, compressors, motors, control gear, etc will all be generating heat when in use. That heat won't be comparable to the heat from a big prime mover diesel, but it's also not going to be completely trivial. If it has rheostatic braking capability, that would probably generate enough heat to completely dry it out over a good day's hard running. That's all assuming that the heat can get around sufficiently to dry out the hidden corners, etc.

There just won't be the thin film of oil over it, as is almost inevitable with most diesels (unless the main transformer blows an oil seal).

 

[kermit]

An electric loco in daily use should be generating quite significant heat internally, likely enough to dry it out relative to one that's sitting out of service for a prolonged period. Transformers, blowers, compressors, motors, control gear, etc will all be generating heat when in use. That heat won't be comparable to the heat from a big prime mover diesel, but it's also not going to be completely trivial. If it has rheostatic braking capability, that would probably generate enough heat to completely dry it out over a good day's hard running. That's all assuming that the heat can get around sufficiently to dry out the hidden corners, etc.

There just won't be the thin film of oil over it, as is almost inevitable with most diesels (unless the main transformer blows an oil seal).

Hmmmmm......enough oily grime flying about in a locomotive's (or multiple unit's, for which heat will be less available) daily working environment to provide a daily barrier against rust....I know what you mean, but this begins to sound like an unattractive environment for passengers to mill about in!

Is there a distinct difference in the time taken for servicing a 50 year old loco in terms of dealing with the effects of corrosion, compared with a newer unit?

 

[Murph]

Hmmmmm......enough oily grime flying about in a locomotive's (or multiple unit's, for which heat will be less available) daily working environment to provide a daily barrier against rust....I know what you mean, but this begins to sound like an unattractive environment for passengers to mill about in!

Is there a distinct difference in the time taken for servicing a 50 year old loco in terms of dealing with the effects of corrosion, compared with a newer unit?

A couple of the Deltics have had a body rebuild, if memory serves. There was a blog out there covering at least one of them being rebuilt, I think by the DPS.

 

[Spagnoletti]

s.

How much effort has to go into keeping these old-timers ship-shape, and are many of them extremely crumbly just under the surface?

As I understand it when in service many locos didn't get much chance to cool down in between duties and as correctly stated above the nice warm interior tended to keep the moisture levels down.
Modernisation era locos are not particularly watertight, and those stored outside, perhaps only being started a dozen times a year, tend to develop streaks on the paintwork very quickly. Soon this leads to corrosion on the bodywork as the rainwater seeps into cracks in the paintwork. Paint bubbles up and cracks some more and pretty quickly the loco starts to looks quite shabby. What's more difficult to deal with is where rainwater gets into places it shouldn't due to bad design - for example between the cab and body on a class 20 or pretty much anywhere on a BRCW loco due to the godawful drainage design in the side louvres. The corrosion this causes requires significant work to put right. Even using tarps isn't a complete solution as condensation occurs during day/night temperature cycles.
All in all it generally feels like a losing battle against the tin worms.