Any other UK units that don't have traction interlock?

[martin2345uk]

So class 373 trains will happily let you pull away with doors open, steps out etc., do any other older UK sets have this? I'm surprised it's not mandated to be honest!

 

[norbitonflyer]

I understood that on some units only the starting signal was interlocked with the doors. Interlocking the traction could cause an immobilsation because of a faulty door, making it impossible either to get the unit back to the depot or to run any other trains through the area.
I've certainly heard of a 313 running empty with all doors open.
There may have to be different safeguards on DOO units.

 

[frankmoh]

Class 150s (and the former 317s) have a cab door that could be used as a passenger door when the cab is not being used (multiple working). Not common to use it nowadays although in the 1980s this was more common from what I have read.

 

[_toommm_]

Class 150/1 have a manually-operated cab-door which isn't interlocked, unlike the 150/2 mentioned above which is interlocked and can be used by passengers when coupled together in multiple. Previously, the 507/508 units had a cab door that originally wasn't interlocked, although I'm not sure if it became interlocked towards the end of their life.

 

[stadler]

The 373s are definitely unique in being the only train with the passenger doors not interlocked. I am quite surprised that the 373s have never been modified. You would think that health and safety regulations would ban it.

Some of the older BREL stock has no cab door interlock (like the 150/1 units mentioned have no cab door interlock although the 150/0 and 150/2 do have cab door interlock) but this is getting very rare as most of those classes have been withdrawn.

The 455s never had the cab door interlocked. On warm summer days on the Dorking to Horsham line there was always some guards that used to leave the cab door open between stops to get a nice breeze in the rear cab. I used to see this right up until 2017 when they were withdrawn.

The 313s and 508s never had a cab door interlock in Connex / London Overground / Silverlink / Southeastern days. Southern modified their units to add a cab door interlock when they received them. I think most other PEP operators also modified theirs.

Every single modern train built since the 1990s has the all doors interlocked including the cab door. The train can not move if even the cab door is open. Trains with cab doors that are not interlocked are a thing of the past.

It is still fairly common in many Mainland European countries and the USA / Canada / Australia / New Zealand to find trains where the cab doors and sometimes the passenger doors too are not interlocked.

 

[TT-ONR-NRN]

It is still fairly common in many Mainland European countries and the USA / Canada / Australia / New Zealand to find trains where the cab doors and sometimes the passenger doors too are not interlocked.

In New South Wales, even on the brand new Hyundai trains introduced in December 2024, it is standard for the guard to stand at the open cab door of the train while it departs until its left the platform.

 

[Clarence Yard]

I understood that on some units only the starting signal was interlocked with the doors. Interlocking the traction could cause an immobilsation because of a faulty door, making it impossible either to get the unit back to the depot or to run any other trains through the area.
I've certainly heard of a 313 running empty with all doors open.
There may have to be different safeguards on DOO units.

Not on any units I’ve ever been involved on. No door link with the signalling system. You can always isolate the door interlock in specific circumstances in order to move the unit away.

As far as 313 units are concerned, I’ve actually seen one passing by in passenger service with all its doors open! That was due to a guard left behind and a faulty interlock. I was trackside and near an SPT at the time and quickly phoned KX Power Box to get it stopped. Apparently their phones were going wild at the time as I wasn’t the only person to spot it!

 

[martin2345uk]

The 373s are definitely unique in being the only train with the passenger doors not interlocked. I am quite surprised that the 373s have never been modified. You would think that health and safety regulations would ban it.

Yes it is quite odd they have never been modified; they are currently modifying them to have ETCS and I would have thought traction interlock would be less complex than that!

 

[skyhigh]

Not on any units I’ve ever been involved on. No door link with the signalling system. You can always isolate the door interlock in specific circumstances in order to move the unit away.

I presume by starting signal they mean the signal buzzer rather than actual signal.

 

[Towers]

HSTs famously had no interlock; the CDL lights merely indicated whether the doors were unlocked but had no effect on whether the train could move (and indeed the CDL could be ‘locked’ with all the doors wide open!).

I understood that on some units only the starting signal was interlocked with the doors. Interlocking the traction could cause an immobilsation because of a faulty door, making it impossible either to get the unit back to the depot or to run any other trains through the area.
I've certainly heard of a 313 running empty with all doors open.

There is a common function which isolates the door interlock to allow a train to be moved in exactly those circumstances.

 

[norbitonflyer]

Not on any units I’ve ever been involved on. No door link with the signalling system. You can always isolate the door interlock in specific circumstances in order to move the unit away.

I meant the signal given by the guard to the driver (as in "ding ding and away") The buzzer isolated when the doors were open

 

[LowLevel]

In New South Wales, even on the brand new Hyundai trains introduced in December 2024, it is standard for the guard to stand at the open cab door of the train while it departs until its left the platform.

Used to be standard here. One too many injuries caused to guards caused by clowns who'd missed the train throwing themselves at them saw it phased out from the 90s into the 2000s.

 

[D365]

HSTs famously had no interlock; the CDL lights merely indicated whether the doors were unlocked but had no effect on whether the train could move (and indeed the CDL could be ‘locked’ with all the doors wide open!).

The ScotRail HSTs were fitted with door interlock as part of the power doors conversion. I assume that door interlock was similarly fitted to the former GWR ’Castle’ and CrossCountry sets.

 

[coppercapped]

The 373s are definitely unique in being the only train with the passenger doors not interlocked. I am quite surprised that the 373s have never been modified. You would think that health and safety regulations would ban it.

Snipped

Yes it is quite odd they have never been modified; they are currently modifying them to have ETCS and I would have thought traction interlock would be less complex than that!

I'm confused... The Class 373 is the original Eurostar train, sometimes known as the E300. Are the surviving trains really being fitted with ETCS?

Anyway, why would the 373 need an interlock between the passenger doors and the traction control when the doors were/are only opened at Waterloo/St Pancras or the Gare du Nord or Bruxelles Midi? (OK, from time to time at Ashford or Lille as well). A fault occurring in the door interlock circuits while moving could mean that the train comes to a stand in the Channel Tunnel - I would suggest that this could be more of a problem than proving the doors are locked before the train moves at terminals where passenger access to the platforms is strictly controlled and staff are on the platforms.

 

[NSEWonderer]

I'm confused... The Class 373 is the original Eurostar train, sometimes known as the E300. Are the surviving trains really being fitted with ETCS?

Anyway, why would the 373 need an interlock between the passenger doors and the traction control when the doors were/are only opened at Waterloo/St Pancras or the Gare du Nord or Bruxelles Midi? (OK, from time to time at Ashford or Lille as well). A fault occurring in the door interlock circuits while moving could mean that the train comes to a stand in the Channel Tunnel - I would suggest that this could be more of a problem than proving the doors are locked before the train moves at terminals where passenger access to the platforms is strictly controlled and staff are on the platforms.

Its quite rare for an interlock fault to develop mid journey and even if it did, most trains have a Traction interlock switch to bypass the fault provided the necessary checks and process has been conducted.

 

[M60lad]

I'm pretty sure that even towards the end of their life the cab doors on Merseyrails 507/508s didn't have interlock fitted as you would often see them leaving and arriving at platforms with the rear cab door open as the odd guard would open it as the train approached the platform.

 

[martin2345uk]

I'm confused... The Class 373 is the original Eurostar train, sometimes known as the E300. Are the surviving trains really being fitted with ETCS?

Anyway, why would the 373 need an interlock between the passenger doors and the traction control when the doors were/are only opened at Waterloo/St Pancras or the Gare du Nord or Bruxelles Midi? (OK, from time to time at Ashford or Lille as well). A fault occurring in the door interlock circuits while moving could mean that the train comes to a stand in the Channel Tunnel - I would suggest that this could be more of a problem than proving the doors are locked before the train moves at terminals where passenger access to the platforms is strictly controlled and staff are on the platforms.

Yes the surviving TMSTs are being fitted with ETCS.

Fair point about the interlock but the 374s have it of course and I don’t believe such an issue has yet occurred.

 

[Clarence Yard]

I meant the signal given by the guard to the driver (as in "ding ding and away") The buzzer isolated when the doors were open

Ah! That makes more sense, thanks.

I don’t know when that was introduced. All the 1970’s era stock were not fitted from new and I am fairly sure a lot of the 1980’s era stock weren’t either.

 

[simonmpoulton]

I'm pretty sure that even towards the end of their life the cab doors on Merseyrails 507/508s didn't have interlock fitted as you would often see them leaving and arriving at platforms with the rear cab door open as the odd guard would open it as the train approached the platform.

Yes the cab doors on the 507/508's if operated using the guards panel do not break the interlock - if they are manually opened using the handle however then yes they do break the interlock.

Also in terms of 150/2's back in the Arriva Trains Wales days i've used the cab door to board even on a single unit although it sounds from other comments that this isnt too common!

 

[John Hardee]

GWR's Night Riviera Sleeper (Class 57 and Mk 3 coaches) has no door interlock also.

 

[Towers]

The ScotRail HSTs were fitted with door interlock as part of the power doors conversion. I assume that door interlock was similarly fitted to the former GWR ’Castle’ and CrossCountry sets.

Indeed, all sliding door conversions had interlock added.

I meant the signal given by the guard to the driver (as in "ding ding and away") The buzzer isolated when the doors were open

There are various classes of train where this isn’t a feature, Voyagers and Class 165 & 166 ‘Turbo’ DMUs being two examples, because they are or were operated under the “10 bells” system whereby the guard uses the buzzer to instruct the driver to close the doors, hence it obviously cannot be interlocked.

 

[Fincra5]

GWR's Night Riviera Sleeper (Class 57 and Mk 3 coaches) has no door interlock also.

It does these days, AFAIK.

 

[43096]

It does these days, AFAIK.

Perhaps you could explain how that is the case given there are no control cables between loco and stock - only air pipes and train supply jumper.