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Class 444/450 Pantograph wells

Brent Goose

Brent Goose

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On Monday’s trip from Weymouth (on diversion via Havant presumably due to engineering work) I ended up in the section where the Pantograph would be so there were no overhead spaces for people’s luggage.

Is this feature because they share a ‘platform’ with a type that does work with OHLE or was there some expectation that the third rail system might be ripped out - which seems unlikely in most of our lifetimes?

(Apologies if this has been discussed before but I didn’t see anything when searching the forum)
 
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pokemonsuper9

pokemonsuper9

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I beleive all (not really old) 3rd rail units are required to be able to become OLE units. I beleive one 707 unit had a pantograph and did some testing on OLE before it was taken off and sent South.
 
B

Bedwyn32

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Yes they do share the shell and body with the class 350. Seimans did the testing of the class 350 here in SWR land as they also had 3rd rail shoes on them at them time.
 
NSEWonderer

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Brent Goose said:
On Monday’s trip from Weymouth (on diversion via Havant presumably due to engineering work) I ended up in the section where the Pantograph would be so there were no overhead spaces for people’s luggage.

Is this feature because they share a ‘platform’ with a type that does work with OHLE or was there some expectation that the third rail system might be ripped out - which seems unlikely in most of our lifetimes?

(Apologies if this has been discussed before but I didn’t see anything when searching the forum)
Click to expand...
Yes still there are spare switches for any future ac conversions. Most 3rd rail units made post 2000s had backup ac bath tub Wells for the pantograph, the 450 Desiro tested use of the AC pantographs back on the original test track abroad before they were removed and sent over.

Same with the recent 701s.
 
Mikey C

Mikey C

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I believe the Gatwick 460s were the only post privatisation EMU not to have a pantograph recess?
 
DelW

DelW

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Brent Goose said:
Is this feature because they share a ‘platform’ with a type that does work with OHLE or was there some expectation that the third rail system might be ripped out - which seems unlikely in most of our lifetimes?
Click to expand...

I can't imagine there was any thought that third rail would be removed within the lifespan of the Desiros, but it would have been commercially beneficial to the owning ROSCO to have the possibility of OHLE conversion.

At the end of lease, if they can't reach a new agreement with a 3rd rail TOC, they can offer the fleet to an OHLE TOC for a fairly small conversion cost. Having that option available might also impact on their price negotiations with the 3rd rail TOC.
 
C

cav1975

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I have often wondered if the extra air turbulence created by these unused pantograph wells has a measurable value, in terms of electricity used, over the unit's lifetime.
 
N

notverydeep

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cav1975 said:
I have often wondered if the extra air turbulence created by these unused pantograph wells has a measurable value, in terms of electricity used, over the unit's lifetime.
Click to expand...
I presume that this was not thought material by the designers because some sort of fairly simple bolt on cover, that would be removed on conversion to AC could have addressed any loss of efficiency?
 
Z

zwk500

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DelW said:
I can't imagine there was any thought that third rail would be removed within the lifespan of the Desiros, but it would have been commercially beneficial to the owning ROSCO to have the possibility of OHLE conversion.

At the end of lease, if they can't reach a new agreement with a 3rd rail TOC, they can offer the fleet to an OHLE TOC for a fairly small conversion cost. Having that option available might also impact on their price negotiations with the 3rd rail TOC.
Click to expand...
And also presumably it's easier to design an AC Unit and then modify it for 3rd rail, than to design a completely new 3rd Rail unit.

Although it's interesting that the Desiros got 4xx TOPS numbers (reserved for DC-only EMUs) if they didn't get pantographs while the Electrostars got 3xx numbers (for AC or Dual-Voltage EMUs) even when not fitted with pantographs. Is there a technical difference in the units that explains why you get 350/450 as a separate class but 377s get subclasses (e.g. 377/1 vs 377/2)?
 
S

swt_passenger

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zwk500 said:
And also presumably it's easier to design an AC Unit and then modify it for 3rd rail, than to design a completely new 3rd Rail unit.

Although it's interesting that the Desiros got 4xx TOPS numbers (reserved for DC-only EMUs) if they didn't get pantographs while the Electrostars got 3xx numbers (for AC or Dual-Voltage EMUs) even when not fitted with pantographs. Is there a technical difference in the units that explains why you get 350/450 as a separate class but 377s get subclasses (e.g. 377/1 vs 377/2)?
Click to expand...
There‘s no logical reason for them having the 4xx designation, we’ve had quite a few inconclusive previous discussions about this very point. TOPS classes are allocated with a certain amount of randomness anyway.
 
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norbitonflyer

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zwk500 said:
And also presumably it's easier to design an AC Unit and then modify it for 3rd rail, than to design a completely new 3rd Rail unit.
Click to expand...
As I understand it, the only differences other than the presence of a pantograph and/or shoes is that a ballast weight is put in the dc units to compensate for the missing transformer and rectifier.

SWT and Gat Ex used the 4xx series for their new units, whereas the two Connex franchises and their successors used the 37x range.
 
S

swt_passenger

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norbitonflyer said:
As I understand it, the only differences other than the presence of a pantograph and/or shoes is that a ballast weight is put in the dc units to compensate for the missing transformer and rectifier.

SWT and Gat Ex used the 4xx series for their new units, whereas the two Connex franchises and their successors used the 37x range.
Click to expand...
I believe the 444 and 450 do not have the ballast, that’s been explained as only an Electrostar thing. The end panel weights of the relevant 350 and 450 carriages are about 4 tonnes different.
 
B

Bletchleyite

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Bedwyn32 said:
Yes they do share the shell and body with the class 350. Seimans did the testing of the class 350 here in SWR land as they also had 3rd rail shoes on them at them time.
Click to expand...

They were also intended originally to be additional 450s before they were diverted to the WCML.

They have run on third rail in service - a few of them were used for the Southern WCML service probably about 15 years ago or thereabouts (I think).
 
3141

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pokemonsuper9 said:
I beleive all (not really old) 3rd rail units are required to be able to become OLE units. I beleive one 707 unit had a pantograph and did some testing on OLE before it was taken off and sent South.
Click to expand...
There was a photo of a class 707 being tested on AC at St. Pancras International Low Level.
 
F

FOH

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Brent Goose said:
On Monday’s trip from Weymouth (on diversion via Havant presumably due to engineering work) I ended up in the section where the Pantograph would be so there were no overhead spaces for people’s luggage.

Is this feature because they share a ‘platform’ with a type that does work with OHLE or was there some expectation that the third rail system might be ripped out - which seems unlikely in most of our lifetimes?

(Apologies if this has been discussed before but I didn’t see anything when searching the forum)
Click to expand...
IIRC there was a hubris for a short period of time that OHLE would be installed between Southampton and Basingstoke replacing the 3rd rail
 
Doomotron

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zwk500 said:
Although it's interesting that the Desiros got 4xx TOPS numbers (reserved for DC-only EMUs) if they didn't get pantographs while the Electrostars got 3xx numbers (for AC or Dual-Voltage EMUs) even when not fitted with pantographs. Is there a technical difference in the units that explains why you get 350/450 as a separate class but 377s get subclasses (e.g. 377/1 vs 377/2)?
Click to expand...

swt_passenger said:
There‘s no logical reason for them having the 4xx designation, we’ve had quite a few inconclusive previous discussions about this very point. TOPS classes are allocated with a certain amount of randomness anyway.
Click to expand...
It is worth keeping in mind though that the first third rail Electrostars were the 375/6s, which are dual-voltage units and therefore do belong in the 3xx range. The rest of the 375s weren't, but putting them in a different class wouldn't have had much of a benefit. TOPS classifications since the 1990s have been mostly pulled out of a hat at random, which explains a lot.
 
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stadler

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pokemonsuper9 said:
I beleive all (not really old) 3rd rail units are required to be able to become OLE units. I beleive one 707 unit had a pantograph and did some testing on OLE before it was taken off and sent South.
Click to expand...
It is actually two 707s (707 001 and 707 002) that are fitted with pantographs. There are some photos and videos of them online doing some tests runs along the Thameslink core and ECML routes. There are also three 701s (701 001 and 701 501 and 701 502) that are fitted with pantographs. These do not seem to have done any testing under overhead wires yet.
 
NSEWonderer

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stadler said:
It is actually two 707s (707 001 and 707 002) that are fitted with pantographs. There are some photos and videos of them online doing some tests runs along the Thameslink core and ECML routes. There are also three 701s (701 001 and 701 501 and 701 502) that are fitted with pantographs. These do not seem to have done any testing under overhead wires yet.
Click to expand...
There has been a 701(701502) thats done testing on a test track at Derby Litchurch Lane with Panto up, but thsse have like 707s all since had the equipment removed before delivery to mainland SWR.


FB_IMG_1746753306745.jpg
 
D

DannyMich2018

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The 30 SE 375/6s were built as dual voltage and were even fitted with pantographs, looking at YouTube many still have them now.
 
3141

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FOH said:
IIRC there was a hubris for a short period of time that OHLE would be installed between Southampton and Basingstoke replacing the 3rd rail
Click to expand...
Yes, the Electric Spine it was called, and it would enable freight to be hauled electrically from Southampton and then beyond Oxford to the Midlands and North. If only Great Western electrification had not cost so much!
 
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Geeves

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cav1975 said:
I have often wondered if the extra air turbulence created by these unused pantograph wells has a measurable value, in terms of electricity used, over the unit's lifetime.
Click to expand...

You'd imagine if aerodynamics was high on the list of importance, the fact the train design is basically a huge brick blasting along at 100mph would be an easier issue to look at (and measure). I doubt an open pantograph well makes any noticeable difference at all.
 
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