Future Class 73 replacement

[brad465]

The 73s still in service are now around 60 years old, so presumably will need replacing before long (some have already been scrapped or preserved). How could they be replaced?

Those that are still needed in third rail land could potentially be replaced by a battery-electric build loco, if the battery can be given enough range, or a tri-mode with OHLE capability added. The latter might be needed if diesel is to be done away with and interchangeability with Merseyrail turf is required (I'm guessing diesel in the tunnels is either prohibited or strongly discouraged).

Then there are the 73s with the Caledonian Sleeper operation. I think for those being replaced with the Class 99 or an similar such loco would be better as third rail is clearly unnecessary on these operations, something that has previously been discussed elsewhere.

 

[Ted633]

Do the 73’s down south have any uses that a modern locomotive cannot carry out? I’m not aware of anything. (Unlike, for example, class 37s on snow plough duties on the Far North Line)
It would be nice to see them replaced by a new bi or tri-mode locomotive. However, I think when they do become life expired, they’ll simply be replaced whatever the run-of-the-mill diesel is (currently the 66)

Personally though, I would put the 73 in with a chance of being the last BR locomotive type in service.

 

[HamworthyGoods]

Do the 73’s down south have any uses that a modern locomotive cannot carry out? I’m not aware of anything. (Unlike, for example, class 37s on snow plough duties on the Far North Line)
It would be nice to see them replaced by a new bi or tri-mode locomotive. However, I think when they do become life expired, they’ll simply be replaced whatever the run-of-the-mill diesel is (currently the 66)

Personally though, I would put the 73 in with a chance of being the last BR locomotive type in service.

I’d suspect the 08s have one of the strongest chances of being the last in service - very low mileage, low speed and basic.

 

[GRALISTAIR]

Personally though, I would put the 73 in with a chance of being the last BR locomotive type in service.

Good old English Electric. My favourite loco of all time.

I would replace with Class 99 - can't see a role for a 3rd rail only/diesel hybrid.

 

[TastyMaltesers]

For the 3rd rail sections, I can't imagine replacing a bi-mode locomotive with something that only runs on diesel would be a good look.

 

[brad465]

For the 3rd rail sections, I can't imagine replacing a bi-mode locomotive with something that only runs on diesel would be a good look.

How easily could a loco that can discharge a battery at the same time as using third rail be made? Such a loco could deploy a higher hp while starting/accelerating, then recharge the rest of the time. On OHLE this probably isn't necessary, but given power limitations on third rail, discharging extra power from the battery in such scenarios will be valuable.

 

[zwk500]

How easily could a loco that can discharge a battery at the same time as using third rail be made? Such a loco could deploy a higher hp while starting/accelerating, then recharge the rest of the time. On OHLE this probably isn't necessary, but given power limitations on third rail, discharging extra power from the battery in such scenarios will be valuable.

Technically? Relatively easy with a modern power control system. Might be a bit more complicated to demonstrated compliant compatibility with the 3rd rail system though.

 

[Bletchleyite]

For the 3rd rail sections, I can't imagine replacing a bi-mode locomotive with something that only runs on diesel would be a good look.

That's literally what happened on Merseyrail when the Network Rail MPVs replaced the 73s and 501 trailers formerly doing Sandite etc. Nobody has really noticed bar enthusiasts, they even have exhaust scrubbers so they can work through the tunnels.

 

[Mikey C]

Do any 73s actually use the third rail now?

 

[43096]

Do any 73s actually use the third rail now?

Yes. The GBRf locos not used on the Caledonian Sleepers work off the third rail whenever possible.

 

[2001olib]

Id image what ever becomes, if anything becomes the new general purpose RA5 loco would replace the 37's and 73's and may also see off some 57's, 66's, 69's and whatever remains of 56's.

 

[HSTEd]

That's literally what happened on Merseyrail when the Network Rail MPVs replaced the 73s and 501 trailers formerly doing Sandite etc. Nobody has really noticed bar enthusiasts, they even have exhaust scrubbers so they can work through the tunnels.

It will be a bit different in the nearly decarbonised railway though.
Lack of third rail capability could end up meaningfully increasing the infrastructure that has to be provided in terms of diesel distribution and dispensing.

 

[zwk500]

It will be a bit different in the nearly decarbonised railway though.
Lack of third rail capability could end up meaningfully increasing the infrastructure that has to be provided in terms of diesel distribution and dispensing.

There's enough diesel distribution for the various freight and departmental services that currently operate. Plenty of RHTTs are diesel-only operated circuits on 3rd rail land. 99% of 'normals' wouldn't bat an eyelid if the 73s were withdrawn - 98% of them probably don't even realise that there are third-rail electric locos still runnnig.

 

[HSTEd]

There's enough diesel distribution for the various freight and departmental services that currently operate.

Well yes, but thats a railway where hundreds of thousands of tonnes of diesel are burned by passenger operations, as well as a lot of freight operations.

With batteries being how they are, we probably aren't far from the point where diesel passenger operations largely cease and even a chunk of revenue freight will go.
Currently the railway uses ~430,000t of diesel per year, with only 124,000t of that used by freight.

We could easily see reductions in diesel use on the railway of 80% or more.

We would be in the realm of diesel distribution and dispensing on the mainline railway being comparable to the tonnage of coal burned on preserved railways (~35,000t per year, showing how bad steam locomotives are in fuel efficiency!)
At that point, pushing to the end of significant diesel use would eliminate a major hassle for the railway as well as political liability.

Plenty of RHTTs are diesel-only operated circuits on 3rd rail land. 99% of 'normals' wouldn't bat an eyelid if the 73s were withdrawn - 98% of them probably don't even realise that there are third-rail electric locos still runnnig.

Yes, and right now the railway's environmental credentials are protected by road fuel use. That shield is disintegrating before our eyes though.

 

[zwk500]

Well yes, but thats a railway where hundreds of thousands of tonnes of diesel are burned by passenger operations, as well as a lot of freight operations.

With batteries being how they are, we probably aren't far from the point where diesel passenger operations largely cease and even a chunk of revenue freight will go.
Currently the railway uses ~430,000t of diesel per year, with only 124,000t of that used by freight.

We could easily see reductions in diesel use on the railway of 80% or more.

We would be in the realm of diesel distribution and dispensing on the mainline railway being comparable to the tonnage of coal burned on preserved railways (~35,000t per year, showing how bad steam locomotives are in fuel efficiency!)
At that point, pushing to the end of significant diesel use would eliminate a major hassle for the railway.

In Southern Land, the vast majority of passenger services are already electric only. Diesels are not used by SE, only used on 2 routes by Southern, and restricted to operations running west of Southampton by SWR. So I wouldn't say that on a regional level there is scope for a vast reduction in diesel use.

When the 73s can no longer be kept running (probably when ETCS tries to be fitted to them), then the options for the duties 73s currently do are as follows:
Depot Shunts: Remotely-operated or autonomous 'tugs'
Stock Moves: Couple up to another unit or spot-hire in freight locos.
RHTT circuits: Use whatever freight locos are used in the region or utilise passenger stock to treat railheads in a different way.

Very few freight flows in the southern region are long enough to make it worth fitting the 3rd rail equipment as opposed to ordering a Bi-Mode (as GBRf have done) as Diesel-Overhead or Battery-Overhead. I don't seen the 73s being replaced with another 3rd-rail capable loco.

 

[JamesT]

Aren’t there a pile of Class 92s in storage? If you wanted a newer third rail locomotive and don’t need the diesel capability, use those?

 

[zwk500]

Aren’t there a pile of Class 92s in storage? If you wanted a newer third rail locomotive and don’t need the diesel capability, use those?

To quote from the Sectional Appendix:

Class 92 locomotives - route availability Class 92 locomotives are permitted to operate/travel over the Kent, Sussex and Wessex Routes as follows:-
...
Operation on the DC power supply
Permitted only between Boundary with Eurotunnel, Saltwood Jn and Mitre Bridge Jn via:-
Tonbridge, Orpington, Shortlands Jn and Herne Hill or Catford Loop and then via Factory Jn, Longhedge Jn and Latchmere Jn.
and
Maidstone East, Swanley, Shortlands Jn and Herne Hill or Catford Loop and then via Factory Jn, Longhedge Jn and Latchmere Jn.
Also permitted between Sevenoaks and Otford Jn via Bat & Ball and Longhedge Jn, Ludgate Jn into Clapham Jn sidings 48 & 49.
South East (Kent, Sussex, Wessex) Territory GI - Dated: 25/09/22

National Electronic Sectional Appendix - Network Rail

The National Electronic Sectional Appendix contains detailed information useful to operators about network capability, as well as other data.

www.networkrail.co.uk

I'm imagining there's a power supply or signalling interference reason (or both) for the restrictionto just 3 variations of route between the Channel Tunnel and North Pole, so to use them widely across the Southern Region would require quite a bit of work.

Also, the 73 being able to work off the juice is rather a handy capability in a number of scenarios, including Depots, Yards, and De-Icing runs.