Why Are Cab Door Handles Levers?

[whhistle]

Click for High Res

Looking at this photo of the Aventra train, I see the cab emergency egress handle (?) is present.
It's also present on the old Turbostar design in pretty much exactly the same way.

The older 165 units have a slightly different design.

But why is it even like that?
Why isn't it like Locos with a key, or a push button?
Is it because it mechanically changes the state of the door so at any point, the door could be opened from the outside?

 

[AM9]

But why is it even like that?
Why isn't it like Locos with a key, or a push button?
Is it because it mechanically changes the state of the door so at any point, the door could be opened from the outside?

Maybe because it will work whatever the electrical state of the trains, i.e. de-wired, power cut auxiliary/emegency on-board power failure. Other wist, there is a catch 22 situation where nobody can get aboard to fix/start the train.

 

[edwin_m]

The Turbostar cab door isn't powered so it would have to be a mechanical release, and it's then opened/closed using the handle on the door. I don't know if the Aventra door is powered, but as suggested it makes sense to have a way of getting into the train even if it is totally dead electrically (and there's probably a similar concern with emergency exit). A 158 has a manual open/close handle that appears to operate the door under power (and goes through the cab wall so it can be set or reset inside or out) but I assume if the train has no power/air it would just mechanically release so the door can be opened by hand. What do the earlier Sprinter types have?

 

[daikilo]

Assuming that what you are refering to is linked to emergency access/egress, then the handle will have to be purely mechanical for the unlock phase. It could have some form of assistance during the opening phase (manual push, spring, stored energy actuator, ...). It will also need type approval so reusing something that is known to work limits risk and time during the process.

That said, the visual of the Aventra must be computer generated so I wouldn't lay too much faith in a detail such as that handle (note the intriguing shape between the roofline and the nose windscreen).

 

[Tomnick]

A 158 has a manual open/close handle that appears to operate the door under power (and goes through the cab wall so it can be set or reset inside or out) but I assume if the train has no power/air it would just mechanically release so the door can be opened by hand. What do the earlier Sprinter types have?

The 'butterfly' on a 158 operates the door normally (from outside or inside, as you say) if there's enough air. Otherwise, there's a pull handle under a flap which firstly isolates the air supply to the door and then provides the force necessary to move the mechanism from the 'over-centre' position, after which the doors can be moved by hand.

Doors on 156s can just be pushed open if there's no air.

On dogboxes, if there's no air, the emergency egress handle has to be used, which releases the air and mechanically forces the door away from the closed position so it can be pulled open by hand. That seems the most comparable to the one pictured above, just without the air to worry about?

 

[Johncleesefan]

And them bowdon cables the open 158s can be just as tough as using an uncoupling rod at times

 

[Domh245]

I don't know if the Aventra door is powered, but as suggested it makes sense to have a way of getting into the train even if it is totally dead electrically

The 'Gen 1' Aventras (345,710,720) have got swing doors. The others look like they've got similar installations to electrostars and turbostars

 

[Bletchleyite]

Whose Aventra is the above meant to be? Not LNR/WMT I guess as there is no gangway and it appears to be 20m?

 

[E_Reeves]

Whose Aventra is the above meant to be? Not LNR/WMT I guess as there is no gangway and it appears to be 20m?

Is it Greater Anglia?

 

[Bletchleyite]

Is it Greater Anglia?

No, theirs are to be 24m as well. 24m units have 5 windows between the doors, the picture shows 4 so a 20m unit.

 

[Domh245]

Whose Aventra is the above meant to be? Not LNR/WMT I guess as there is no gangway and it appears to be 20m?

It's a generic marketing one I think. It's what was used as a placeholder for the GA Aventras on some railway news sites before the actual renders were released

 

[pompeyfan]

Desiros use a T/L key to operate the door electronically. If an overnight isolation has taken place the flap for the emergency egress has to be uncovered and the egress pulled.

 

[physics34]

Later 170s/171s, 387s and 377s have air assisted cab doors with door button as well as a lever on the inside

 

[Fincra5]

Its useful when the train is berthed and has no power because it's just simple mechanical plug door. You can lock it internally or externally for security. Opening it on a 377 would cause an interlock loss, so power cuts out.

 

[Kneedown]

And them bowdon cables the open 158s can be just as tough as using an uncoupling rod at times

Many's the time i've had to climb around the front and gain access from the gangway door!
A little tip. If the leading cab butterfly doesn't work due to lack of air, try one of the centre one's. They often seem to retain air a little longer for some reason.

 

[muz379]

Many's the time i've had to climb around the front and gain access from the gangway door!
A little tip. If the leading cab butterfly doesn't work due to lack of air, try one of the centre one's. They often seem to retain air a little longer for some reason.

Same here , ive seen the handles break off the end of the bowdon cables without popping the door mechanism open .

The look passengers give you when you tell them the train is late because the traincrew cannot get inside .