Could a unit with offset gangways be built?

[GLC]

I’ve read a lot of threads recently where the topic of the pros and cons of gangways have been discussed, atleast with regards to drivers and guards etc. Units with gangways tend to have cramped cabs for drivers, even if they are built with a partition that can be kept open ala Sprinters. Obviously gangways are typically built to be central on the unit so orientation is irrelevant when coupling together, but that got me thinking…

A lot of modern units have powered gangways which extend to connect to the leading unit. Since this is atleast somewhat battle tested technology (the 380s have been doing this for 10 years now) could a unit be built where the gangway is offset to the right of the unit, and extends diagonally left to meet a reciprocating gangway in the middle of the unit. This would give a driver near 50% frontal area dedicated to the cab, sort of like the new Merseyrail units have(although they are for emergency exit only I understand). Multiple working outwith a units own class does not seems to be a particular concern to TOCs these days so an unusual setup for gangways wouldn’t seem to be an issue there.

I realise this might sound a bit fantastical, and equally anything is possible if you are prepared to spend money, but I was just wondering if this is something that had been tried or developed before by anyone?

 

[Bletchleyite]

I think the passengers would end up squashed at the first corner?

 

[hexagon789]

I think the passengers would end up squashed at the first corner?

I can think of a design mitigation for that but potentially at the expense of one of the initial problems you're trying to solve with this 'offset' design - driver visibility.

Unless... you had a completely sheer gangway? Now that would be an interesting experience.

(But I don't think such a material exists that is fully see-through AND has the necessary strength.)

I’ve read a lot of threads recently where the topic of the pros and cons of gangways have been discussed, atleast with regards to drivers and guards etc. Units with gangways tend to have cramped cabs for drivers, even if they are built with a partition that can be kept open ala Sprinters. Obviously gangways are typically built to be central on the unit so orientation is irrelevant when coupling together, but that got me thinking…

A lot of modern units have powered gangways which extend to connect to the leading unit. Since this is atleast somewhat battle tested technology (the 380s have been doing this for 10 years now) could a unit be built where the gangway is offset to the right of the unit, and extends diagonally left to meet a reciprocating gangway in the middle of the unit. This would give a driver near 50% frontal area dedicated to the cab, sort of like the new Merseyrail units have(although they are for emergency exit only I understand). Multiple working outwith a units own class does not seems to be a particular concern to TOCs these days so an unusual setup for gangways wouldn’t seem to be an issue there.

I realise this might sound a bit fantastical, and equally anything is possible if you are prepared to spend money, but I was just wondering if this is something that had been tried or developed before by anyone?

I admire the idea, I really do. In my mind I'm struggling to rationalise a design that would solve all the initial issues that are trying to be solved here without introducing further ones.

I did think about curving one side of the unit in slightly on the side where the gangway would project from in order to have a slight curve on the gangway and preserve its width throughout, but that would be at the expense of vision to the secondman's side even when the gangway was retracted.

A simple diagonal design would I think need a substantial projection and redesign of how they support themselves to work.

I would love to see a mock-up though, it would be a interesting concept and rather more for a practical purpose than some ideas in this sub-forum.

 

[zwk500]

Normal gangways (including the 380s) are fixed at the bottom to support the weight of somebody moving through between carriages. Most units in Britain don't actually move the gangways themselves, the 380s just move the top of the gangway back a bit to clear the Driver's view. Therefore you would either need to mount the bottom of the diagonal gangway in the middle anyway (therefore making an offset gangway pointless), or have a very strong mechanical system to retract the entire gangway at an oblique angle. It's theoretically possible, of course, but not really worth the money, because of the high twisting forces that would be involved.

Old TPOs had offset gangways, but they stayed the same side of the train and were offset deliberately to not interwork with centrally gangwayed stock.

 

[XAM2175]

To the best of my knowledge the only workable solution for allowing a reasonably-sized cab and a gangway is the one that ABB Scandia put into production as the Flexliner (of which the most well-known model is probably the DSB IC3).

Huge rubber gasket around the entire front of the train forms the gangway, and the entire front of the cab forms the door:


Control stand and driver's seat are fixed to the door, which is hinged at the left-hand side (as viewed from the driver's position):

(observe the central driving position and the spacious desktop for the driver)

When units are coupled, the doors are opened (and some partitions are moved about, etc) and voila, huge gangway ready for use:

 

[61653 HTAFC]

One obvious problem would be that a gangway offset to the right would need the corresponding gangway on the other unit to be offset to the left (from the point of view of that unit's cab).

 

[O L Leigh]

The problem is that you do still need a secondman's/non-driving position as sometimes there needs to be two in the cab with both afforded a forward view (e.g. for route learning and driver training/assessment). Therefore I'm not sure that an offset gangway could be made to work. What would help, though, is not making them so flipping massive such that they impinge on the driver's space and view of the road ahead.

 

[Western Lord]

To the best of my knowledge the only workable solution for allowing a reasonably-sized cab and a gangway is the one that ABB Scandia put into production as the Flexliner (of which the most well-known model is probably the DSB IC3).

Huge rubber gasket around the entire front of the train forms the gangway, and the entire front of the cab forms the door:


Control stand and driver's seat are fixed to the door, which is hinged at the left-hand side (as viewed from the driver's position):

(observe the central driving position and the spacious desktop for the driver)

When units are coupled, the doors are opened (and some partitions are moved about, etc) and voila, huge gangway ready for use:

So passengers have to pass by two filthy, squashed bug infested cab fronts whilst trying to avoid snagging their cardies on the windscreen wipers!

 

[XAM2175]

So passengers have to pass by two filthy, squashed bug infested cab fronts whilst trying to avoid snagging their cardies on the windscreen wipers!

No, they're covered by a moveable partition, of which I couldn't find a photograph. I should have been more clear, sorry.

 

[pdeaves]

One obvious problem would be that a gangway offset to the right would need the corresponding gangway on the other unit to be offset to the left (from the point of view of that unit's cab).

No, because the proposal is to move them diagonally to meet, effectively passing in front of the driver's window in each case when two units are coupled.

The 'second person in the cab' issue could be solved through having a window in the gangway door, perhaps?

 

[JohnElliott]

Come to think of it, how did the second person in the cab cope in a 4COR?

 

[whoosh]

I'd like to know how evacuations work with 777s when they are working in multiple. In tunnels.

 

[Bletchleyite]

I'd like to know how evacuations work with 777s when they are working in multiple. In tunnels.

There is a retracting gangway "floor" to get between the units, or you exit from either end (as they will never work in service in 3s). It's quite a clever design overall. Would be no good on the move due to the amount of movement, though.

 

[XAM2175]

There is a retracting gangway "floor" to get between the units, or you exit from either end (as they will never work in service in 3s). It's quite a clever design overall. Would be no good on the move due to the amount of movement, though.

I'd be curious to know when that solution was used, now you mention it. The earliest I can think of was EDI's M-set units for Sydney in 2002.

 

[YorksLad12]

I’ve read a lot of threads recently where the topic of the pros and cons of gangways have been discussed, atleast with regards to drivers and guards etc. Units with gangways tend to have cramped cabs for drivers, even if they are built with a partition that can be kept open ala Sprinters. Obviously gangways are typically built to be central on the unit so orientation is irrelevant when coupling together, but that got me thinking…

A lot of modern units have powered gangways which extend to connect to the leading unit. Since this is atleast somewhat battle tested technology (the 380s have been doing this for 10 years now) could a unit be built where the gangway is offset to the right of the unit, and extends diagonally left to meet a reciprocating gangway in the middle of the unit. This would give a driver near 50% frontal area dedicated to the cab, sort of like the new Merseyrail units have(although they are for emergency exit only I understand). Multiple working outwith a units own class does not seems to be a particular concern to TOCs these days so an unusual setup for gangways wouldn’t seem to be an issue there.

I'd had a similar thought, of a two-thirds cab and a one-third gangway (a bit like the toilets in the centres of a 158, or the cafe-bar area on LNER's Azumas); but...

One obvious problem would be that a gangway offset to the right would need the corresponding gangway on the other unit to be offset to the left (from the point of view of that unit's cab).

... while the offsetting would be easy enough at either ends and not much different to now (cab on the left, facing forward), the problem is that you can only couple up one way so you'd have to make sure your units were always the right way round to match the gangways up. Not impossible, but time consuming (especially if you get it wrong on terminal platforms).

 

[61653 HTAFC]

No, because the proposal is to move them diagonally to meet, effectively passing in front of the driver's window in each case when two units are coupled.

The 'second person in the cab' issue could be solved through having a window in the gangway door, perhaps?

That sounds like it would fall into the "too complicated for the minimal benefit" category then. If it ain't broke...

 

[whoosh]

There is a retracting gangway "floor" to get between the units, or you exit from either end (as they will never work in service in 3s). It's quite a clever design overall. Would be no good on the move due to the amount of movement, though.

Ah I see, thanks for that, so there is a ladder for exit straight on the track but also a "floor" to access across to the other unit if coupled.
I've seen pictures of the ladder, but not of the unit to unit floor arrangement. Do you know of any?