Class455
Established Member
- Joined
- 19 May 2016
- Messages
- 1,398
I've often wondered recently why the Class 455's (and subsequently the Class 456's) use pipes and jumpers when coupling instead of automatic tightlock couplers? Especially when you consider that the technology for simpler coupling existed from the late 1970's and feature on similar aged EMU's such as the Class 317 and 319, and even their predecessors on the South Western Region, the Class 508's.
Whilst attaching and detaching a pair of Class 455's doesn't take much longer than a 377 for example, when you also think of the benefits of automatic tightlock couplers had over pipes and jumpers it does make me wonder why BR's engineers back in 1982 decided to fit the 455's with the latter when designing them. For a start, the Class 456's were supposed to have a similar front end to the Class 321's, but ultimately needed a completely different front end design to accommodate the pipes and jumpers required to work with Class 455's.Also, with the benefit of hindsight, 455's could have worked in multiple with different units both in service and in emergency situations, such as Class 319's when they were with Connex South Central/Southern, and could have worked with the likes of Class 375's before they were fitted with Dellner couplers and Networkers.
You also wonder how much time this would have saved during the overall attachment and detachment process for the 455's, especially as station staff needed to learn how to attach/remove the pipes and jumper couplers, whereas for example it's far easier to split and attach trains with automatic tightlock couplers as staff would have just needed to guide the driver to couple up to the unit in front and then ease up and pull away. I think I'm right in saying that if the 455's came with automatic tightlock couplers, the competency to split and attach them would have been the same as 377's and 450's, therefore knowledge wouldn't be lost in certain locations. And the electrical connection would have been made simply by pressing a "couple" button in the cab rather than needing to have jumper cables plugged together.
I did wonder if the reason was because it was a traditional Southern region thing to have, considering the 455's were being introduced around Slammers which used pipes and jumpers, but this wasn't the case with the 508's and units that followed just a few years later like the 319's which were fitted with automatic couplers. So was there actually a specific reason behind why 455's used pipes and jumpers?
Whilst attaching and detaching a pair of Class 455's doesn't take much longer than a 377 for example, when you also think of the benefits of automatic tightlock couplers had over pipes and jumpers it does make me wonder why BR's engineers back in 1982 decided to fit the 455's with the latter when designing them. For a start, the Class 456's were supposed to have a similar front end to the Class 321's, but ultimately needed a completely different front end design to accommodate the pipes and jumpers required to work with Class 455's.Also, with the benefit of hindsight, 455's could have worked in multiple with different units both in service and in emergency situations, such as Class 319's when they were with Connex South Central/Southern, and could have worked with the likes of Class 375's before they were fitted with Dellner couplers and Networkers.
You also wonder how much time this would have saved during the overall attachment and detachment process for the 455's, especially as station staff needed to learn how to attach/remove the pipes and jumper couplers, whereas for example it's far easier to split and attach trains with automatic tightlock couplers as staff would have just needed to guide the driver to couple up to the unit in front and then ease up and pull away. I think I'm right in saying that if the 455's came with automatic tightlock couplers, the competency to split and attach them would have been the same as 377's and 450's, therefore knowledge wouldn't be lost in certain locations. And the electrical connection would have been made simply by pressing a "couple" button in the cab rather than needing to have jumper cables plugged together.
I did wonder if the reason was because it was a traditional Southern region thing to have, considering the 455's were being introduced around Slammers which used pipes and jumpers, but this wasn't the case with the 508's and units that followed just a few years later like the 319's which were fitted with automatic couplers. So was there actually a specific reason behind why 455's used pipes and jumpers?
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