Air hoses on front of units (and locos)

[py_megapixel]

On the front of this class 455 an air hose is clearly visible (credit to Matt Buck on Wikipedia for the photo)

What are they for, and why do some units have them (older ones) and some not?

 

[DarloRich]

for connecting to class 33 or 73 in them olden days?

 

[swt_passenger]

It‘s how the brake system connects when running in multiple. Just like on freight wagons? Modern units have air connections integral with the couplers.

 

[Neptune]

If you look at a similar class 317 without the air hoses on the front you will see that the coupler has the electrical box underneath which does the same job.

The class 456 which has a 321 style front end also has the waist height jumpers to allow it to couple electrically to a 455.

 

[Tynwald]

Its the main res pipe. brake control is done electricaly through the jumper. Other more modern (and some older) units it is all done through the autocoupler. When these units were built Southern region did not want autocouplers. All other regions did, hence 313, 507s, 317 etc had full autocouplers.

 

[JonathanH]

Its the main res pipe. brake control is done electricaly through the jumper. Other more modern (and some older) units it is all done through the autocoupler. When these units were built Southern region did not want autocouplers. All other regions did, hence 313, 507s, 317 etc had full autocouplers.

It is worth noting that the 508s operated on the South Western division of the Southern region with Autocouplers and the Southern region then decided not to continue using these when specifying the 455s.

 

[swt_passenger]

It is worth noting that the 508s operated on the South Western division of the Southern region with Autocouplers and the Southern region then decided not to continue using these when specifying the 455s.

Same sort of corporate mentality that led to building Mk1 coaches well past their sell by date?

 

[61653 HTAFC]

Higher level jumpers and pipes were favoured on the Southern region because of the live rails I believe. The 141s also had multiple working jumpers visible on the front until they were refurbished and had standard BSI couplers fitted, which rendered the jumpers obsolete. This despite never working in 3rd rail areas (don't think they ever made it to Chester or Hunts Cross!).

 

[Richard Scott]

Higher level jumpers and pipes were favoured on the Southern region because of the live rails I believe. The 141s also had multiple working jumpers visible on the front until they were refurbished and had standard BSI couplers fitted, which rendered the jumpers obsolete. This despite never working in 3rd rail areas (don't think they ever made it to Chester or Hunts Cross!).

However, they couldn't get over the ETH jumper problem with the 4-TC units meaning someone still had to connect/disconnect that by being in the 4 foot.

 

[43096]

However, they couldn't get over the ETH jumper problem with the 4-TC units meaning someone still had to connect/disconnect that by being in the 4 foot.

Wouldn’t buckeye release when uncoupling mean a visit to the 4ft regardless?

 

[Richard Scott]

Wouldn’t buckeye release when uncoupling mean a visit to the 4ft regardless?

Should be able to do that from the platform - just pull the chain? Not that I've tried it mind! Even if did have to get into 4ft wouldn't need to be live rail side whereas ETH needs connecting both sides.

 

[JonathanH]

In the carriage working notices, there did used to be some notes about which side the jumpers are meant to be attached for specific trains to avoid the need for a "wrong side" detachment of the jumper cables. I seem to recall instances of the shunter at Redhill uncoupling 1963-stock by exiting the offside crew door, walking along the step board and detaching the jumper cables. The steps on the front of the 455 are visible in the picture the OP posted - an offside detachment doesn't look particularly feasible.

 

[edwin_m]

Should be able to do that from the platform - just pull the chain? Not that I've tried it mind! Even if did have to get into 4ft wouldn't need to be live rail side whereas ETH needs connecting both sides.

But an autocoupler with electrical connections is safest of all, as it's coupled by driving the trains together and uncoupled with a button in the cab.

 

[Richard Scott]

But an autocoupler with electrical connections is safest of all, as it's coupled by driving the trains together and uncoupled with a button in the cab.

Agreed, just that wasn't an option on older stock!

 

[edwin_m]

Agreed, just that wasn't an option on older stock!

It was fitted to the 507/508 fleet which the Southern got rid of in favour of the 455s.

 

[Richard Scott]

It was fitted to the 507/508 fleet which the Southern got rid of in favour of the 455s.

No, I was referring back to mark 1 derived stock as started with comment about having to connect ETH cables on 4-TC stock. Perhaps I should have been a bit clearer?

 

[Journeyman]

Higher level jumpers and pipes were favoured on the Southern region because of the live rails I believe.

Only on the EPB units built from 1951 onwards. Earlier Southern EMUs had brake pipes on the buffer beams, requiring track level access for connecting/disconnecting, and chain-link couplings. The only things at high level were control, power and lighting jumpers.

 

[JohnElliott]

It is worth noting that the 508s operated on the South Western division of the Southern region with Autocouplers and the Southern region then decided not to continue using these when specifying the 455s.

Same sort of corporate mentality that led to building Mk1 coaches well past their sell by date?

As I recall reading, it was because the autocouplers proved not to be reliable when coupling on a curve - they would connect mechanically but not electrically. After a while a fitter had to be present any time two units were coupled, in case of malfunctions. Hence the reversion to plugs and sockets.

 

[big all]

Only on the EPB units built from 1951 onwards. Earlier Southern EMUs had brake pipes on the buffer beams, requiring track level access for connecting/disconnecting, and chain-link couplings. The only things at high level were control, power and lighting jumpers.

yes indeed up until subs you had a power train line jumper cab level that meant as long as you had one shoe on the juice rail over all the units you had line voltage
you also as said had the lighting jumper and from memory the control jumper was 8 wires ??

 

[Journeyman]

As I recall reading, it was because the autocouplers proved not to be reliable when coupling on a curve - they would connect mechanically but not electrically. After a while a fitter had to be present any time two units were coupled, in case of malfunctions. Hence the reversion to plugs and sockets.

How come that wasn't a problem elsewhere?

 

[cjmillsnun]

How come that wasn't a problem elsewhere?

It probably was a problem elsewhere, however the sheer volume of traffic on the peaks in the southern meant they wanted something tried and tested.

 

[JohnElliott]

How come that wasn't a problem elsewhere?

Because, IIRC, Southern timetables relied on coupling and dividing trains regularly through the day, while elsewhere coupling / uncoupling was less frequent and mainly took place in depots where mechanical attention was easier to come by.

 

[swt_passenger]

As I recall reading, it was because the autocouplers proved not to be reliable when coupling on a curve - they would connect mechanically but not electrically. After a while a fitter had to be present any time two units were coupled, in case of malfunctions. Hence the reversion to plugs and sockets.

Makes sense, and that’s also happened with modern units such as Desiros, but they've overcome the problems eventually.

 

[Tynwald]

The 508 were an unwanted gift to the Southern, and was completely away from there very backward thinking. They were all originaly ordered for Merseyrail to replace both the 502 & 503 units. But then MPTE couldn't afford them all, so a new home had to be found for them. They offloaded them to Merseyrail as soon as they could. It is suprising how much old (ex 4SUB I think) equipment was used in 455, including traction motors, compressors, contactors, and reversers/divert switches.