IET Clearances queries

[TheWalrus]

Good Evening all

I’m just wondering if IETs are cleared for the Portsmouth-Cardiff route? I know there were issues with HSTs going via Hamble and certain bogies but I can’t find anything anywhere to suggest the IETs couldn’t run Cardiff-Portsmouth in terms of clearance. With 5 carriages it would make sense perhaps?

 

[D6975]

A 5 car IET is approx 15m longer than a 5 car turbo rake, so you might have issues there.

 

[TheWalrus]

A 5 car IET is approx 15m longer than a 5 car turbo rake, so you might have issues there.

Possibly but have longer trains not used the route south of Westbury before?

 

[swt_passenger]

Good Evening all

I’m just wondering if IETs are cleared for the Portsmouth-Cardiff route? I know there were issues with HSTs going via Hamble and certain bogies but I can’t find anything anywhere to suggest the IETs couldn’t run Cardiff-Portsmouth in terms of clearance. With 5 carriages it would make sense perhaps?

They are not currently cleared according to the sectional appendix. That doesn’t mean they cannot ever be cleared in the future. 23m coaching stock is cleared, eg Mk 3 based 442s, it was only the HST power cars that didn’t fit. It’s been alleged previously that IET vehicles are supposed to be able to go anywhere a Mk 3 can.

 

[Parallel]

I don’t know for sure but would imagine there would be issues with the curvature of the platforms at Portsmouth & Southsea station. This caused issues and Turbos were unable to run there for some time.

 

[Snow1964]

IETs are fully cleared on Westbury-Cardiff section, and are seen daily, although many between Westbury and Bathampton are empty to/from Stoke Gifford.

I don't believe anything longer than 23m is currently cleared south of Westbury, but I don't know if that is never been tested so not approved, or physically don't fit without clearance modifications.

I suspect anywhere a wide 23m 165 and 166 can go, could also take an IET as their swept path is rumoured to be no bigger. Although longer the IETs are narrower by about 11cm (4.5 inches). The passenger doors are also roughly in same position as on HST and 442 coaches which are (or were) approved to Portsmouth, the IETs extra length is beyond the doors.

 

[zwk500]

I wouldn't be surprised if there were problems with tight platforms between St Denys and Fareham, and the reverse curves at Portsmouth & Southsea might need the attention of an angle grinder to get through. The restrictions sheet when 80Xs first went out on the ECML was rather long, and AIUI it was a mix of better data and some remedial attention to the coping stones to get the restrictions cleared.

My understanding with the HSTs was that it was specifically short swing link bogies that were the problem, and something in the back of my mind says there was interaction with the third rail that fouled the clearances but I might be very wrong on both of those points.

In principle, if there was a need for GWR to put a 5-car on the diagram, there shouldn't be major issues getting them cleared by all 3 possible routes (Botley, Netley, and Southampton Airport Parkway), but it may be more than a pure paperwork exercise.

 

[Ashley Hill]

My understanding with the HSTs was that it was specifically short swing link bogies that were the problem, and something in the back of my mind says there was interaction with the third rail that fouled the clearances but I might be very wrong on both of those points.

IIRC it’s the long swing link bogies that were the problem. During the 2015 diversions a LSL set made it as far as Andover (going to Waterloo) and was terminated there.

 

[MotCO]

My understanding with the HSTs was that it was specifically short swing link bogies that were the problem, and something in the back of my mind says there was interaction with the third rail that fouled the clearances but I might be very wrong on both of those points.

I think that there was a problem with certain HSTs being able to access Waterloo when on diversion, and this did relate to clearance issues with the third rail.

 

[zwk500]

IIRC it’s the long swing link bogies that were the problem. During the 2015 diversions a LSL set made it as far as Andover (going to Waterloo) and was terminated there.

That makes sense - the long swing link would have greater movement/throw or something. I must have got confused with Short Swing link being the permitted ones. Thanks for the knowledge!

I think that there was a problem with certain HSTs being able to access Waterloo when on diversion, and this did relate to clearance issues with the third rail.

Thanks!

 

[Snow1964]

I think IETs have worked Reading West - Basingstoke - Eastleigh depot, so are presumably cleared over third rail.

Basingstoke - Laverstock (Salisbury) - Southampton had huge amount of rebuilt bridges and clearance work about 5 years ago. Not for IETs but for high containers to the docks (W10 or W12 ?).

South of Eastleigh and St Denys, via Fareham, to Portsmouth has been cleared for 442, 444 and more recently 165, 166.

I suspect therefore that clearing Westbury - Portsmouth (and Castle Cary - Weymouth) is more a paperwork exercise, as never yet been needed so hasn't been done, than rejected because will require £millions in physical alterations.

 

[swt_passenger]

I wouldn't be surprised if there were problems with tight platforms between St Denys and Fareham, and the reverse curves at Portsmouth & Southsea might need the attention of an angle grinder to get through. The restrictions sheet when 80Xs first went out on the ECML was rather long, and AIUI it was a mix of better data and some remedial attention to the coping stones to get the restrictions cleared.

My understanding with the HSTs was that it was specifically short swing link bogies that were the problem, and something in the back of my mind says there was interaction with the third rail that fouled the clearances but I might be very wrong on both of those points.

There are two issues, HST coaches could only go over third rail with the SSL bogies - that was a general restriction everywhere in third rail land. Then once you’d got your sets organised with the correct bogies they were still subject to other gauging or weight restrictions on a route by route basis, typically caused by the power cars, and the power cars (but not the coaches) happened to be gauge restricted on the Netley line - that’s why suggestions to use short HSTs on Portsmouth Cardiff have always been thought to be unlikely.

But HSTs have been to Portsmouth Harbour itself without difficulty getting through Ports & SS, back in Virgin days, and also on FGW Football specials, running via Eastleigh & Botley. So not regular appearances but certainly possible.

 

[Clarence Yard]

Having gone through the whole West Turbo clearance saga, I wouldn’t fancy it as being an easy job. In general on the WR, where the IET units got cleared beforehand, the Turbos has an easier ride. It doesn’t quite work the other way around so, from experience, I would expect some issues, especially with the throw on curves. Stepping distances might be a bit interesting in places.

I’m not sure why you would want to do it. 300 seat units with a long door cycle where ideally you want a 400 (2+2) seat unit with a faster door operation? Doesn’t seem sensible to me - I would rather make the case for something more suitable for that service.

 

[Pokelet]

Did the IET's ever get cleared through to Pembroke Dock, I believe it was an issue with Narberth tunnel?

 

[_toommm_]

Did the IET's ever get cleared through to Pembroke Dock, I believe it was an issue with Narberth tunnel?

They did - see the below link for GWR Saturday services from Pembroke Dock:

Realtime Trains | Departures from Pembroke Dock all day on 09/09/2023

Train information at Pembroke Dock all day on 09/09/2023. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk

 

[Pokelet]

Ah, there's me checking last Saturday

Realtime Trains | Departures from Pembroke Dock all day on 26/08/2023

Train information at Pembroke Dock all day on 26/08/2023. From Realtime Trains, an independent source of train running info for Great Britain.

www.realtimetrains.co.uk