Why do Class 380s have tapered bodysides when other Desiros don't?

[Bletchleyite]

Question as per the subject really - why do Class 380s have tapered (sloped) bodysides when other Desiros don't (they are vertical)?

 

[Clarence Yard]

I would have thought it was the 23m car length of a cl.185/380/444 compared to the 20m length of the other Desiro classes.

 

[Bletchleyite]

I would have thought it was the 23m car length of a cl.185/380/444 compared to the 20m length of the other Desiro classes.

Neither classes 185 nor 444 have tapered bodysides (though they are very narrow - 2.68m - which I think makes them the narrowest UK mainline stock).

By "tapered" I mean sloped in towards the cantrail, not tapered at the ends to avoid whacking the overthrow on the platform which I think all Desiros are, and indeed most other UK stock too (Classes 195, 331 and Pendolinos are noticeable for not being - they are the same profile for the full vehicle length).

 

[nlogax]

I can't help but think there's a clue in this FOI request from 2010

https://www.whatdotheyknow.com/request/new_class_380_trains_areas_of_us#incoming-116314

"The new class 380 trains have been procured with the intent of a "go
anywhere" capability, enabling them if practical and appropriate to
operate on any of the electrified routes in Scotland, and indeed any
routes which will be electrified in future."

 

[a_c_skinner]

trains have been procured with the intent of a "go anywhere" capability,

Which rather begs the (off topic) question of why all trains are not specified to "go anywhere". Back on topic does the 380 suffer from this go anywhere design and by extension would others?

 

[mmh]

Which rather begs the (off topic) question of why all trains are not specified to "go anywhere". Back on topic does the 380 suffer from this go anywhere design and by extension would others?

The obvious example to me of units that suffer from a go anywhere design are all the reduced height BR EMUs. 313, 507 and the others with the same bodyshell.

Suffer is probably harsh here though!

 

[snookertam]

I think the answer about the 'go anywhere' specification might be pretty accurate. I also wonder if there was an intention to try and make the units as aerodynamic (and there as energy efficient) as possible. I think it was Transport Scotland who made the specifications.

Not sure if a tapered bodyside would make the train any more aerodynamic, but you'll also notice that the front ends are also sloping despite having the gangway connections, which was done with aerodynamics in mind. They could have just repeated the class 350 design, but instead Transport Scotland made a series of additional requirements which resulted in the class 380.

 

[Clarence Yard]

Neither classes 185 nor 444 have tapered bodysides (though they are very narrow - 2.68m - which I think makes them the narrowest UK mainline stock).

By "tapered" I mean sloped in towards the cantrail, not tapered at the ends to avoid whacking the overthrow on the platform which I think all Desiros are, and indeed most other UK stock too (Classes 195, 331 and Pendolinos are noticeable for not being - they are the same profile for the full vehicle length).

Apologies. I thought you were referring to the tapered ends.

 

[RailWonderer]

They are tapered so if any more of the Scotrail network were to be electrified, they could be used on routes with a narrower loading gauge as I suspect Scotland has.
Also if they left and went south one day they could.

 

[Bletchleyite]

Apologies. I thought you were referring to the tapered ends.

No worries, I thought you might have thought that

 

[fgwrich]

Weren't the 380s considered something of a Desiro Mk2 by Siemens, with some of it's development leading to the Desiro City 7XX fleet we have today?

 

[Bletchleyite]

Weren't the 380s considered something of a Desiro Mk2 by Siemens, with some of it's development leading to the Desiro City 7XX fleet we have today?

I think it was more that ScotRail insisted that they didn't want a Desiro City because it was an unproven design, so what Siemens offered them was a Desiro City body (the very long windows are a giveaway) with standard Desiro running gear.

What that doesn't explain, though, is why the bodyshell is a distinctly different shape to all other UK Desiros.

 

[LOL The Irony]

Weren't the 380s considered something of a Desiro Mk2 by Siemens, with some of it's development leading to the Desiro City 7XX fleet we have today?

I think it was more that ScotRail insisted that they didn't want a Desiro City because it was an unproven design, so what Siemens offered them was a Desiro City body (the very long windows are a giveaway) with standard Desiro running gear.

What that doesn't explain, though, is why the bodyshell is a distinctly different shape to all other UK Desiros.

I always thought they were a crossover between the Desiro UK & Desiro City. Like later model Mk2 Mazda MX5's.

 

[380101]

They are tapered so if any more of the Scotrail network were to be electrified, they could be used on routes with a narrower loading gauge as I suspect Scotland has.
Also if they left and went south one day they could.

The 380s will never leave Scotland as part of the lease deal is Transport Scotland "buy" the 38 units for a £1 after 25years and they become a Transport Scotland owned assest for the benefit of Scotland.

 

[LOL The Irony]

The 380s will never leave Scotland as part of the lease deal is Transport Scotland "buy" the 38 units for a £1 after 25years and they become a Transport Scotland owned assest for the benefit of Scotland.

They have the option to, like all other leased rolling stock in the UK.

 

[380101]

They have the option to, like all other leased rolling stock in the UK.

25 year lease deal with Transport Scotland buying the fleet for £1 at the end of it. Very unlikely that they'll not buy the fleet given their reliability and quality compared to many other 3rd gen EMU fleets.

 

[hwl]

They have the option to, like all other leased rolling stock in the UK.

Unlike most other stock...
Only 385s 800s 801s 700s 345s 378s and 710s have that kind of clause in.

Most stock doesn't...

 

[LOL The Irony]

Unlike most other stock...
Only 385s 800s 801s 700s 345s 378s and 710s have that kind of clause in.

Most stock doesn't...

The 365's?

 

[Bletchleyite]

The 365's?

That was different again - the Government had to buy them, I believe, and for more than a quid!

 

[hwl]

That was different again - the Government had to buy them, I believe, and for more than a quid!

Exactly. Alot more than scrap value!

The desiro, electrostar, turbostar, voyager, meridian, cordia, juniper and pendolino fleets do not have any kind of clause.

 

[hexagon789]

25 year lease deal with Transport Scotland buying the fleet for £1 at the end of it. Very unlikely that they'll not buy the fleet given their reliability and quality compared to many other 3rd gen EMU fleets.

A quid seems like a right bargain!

 

[Bletchleyite]

A quid seems like a right bargain!

I think I can work out why they have done it that way - it's a bit like an Islamic "mortgage" in not actually being debt, but instead a 25 year lease followed by a purchase below actual value. It's the same thing in many ways - you pay an amount per month and get it at the end - the difference being (a) that you don't gain equity - you own nothing until that final payment, (b) you aren't paying interest as such but a lease fee, which it's why it's OK for Muslims, but in this case most importantly (c) it doesn't go on the books as borrowing.

 

[hexagon789]

I think I can work out why they have done it that way - it's a bit like an Islamic "mortgage" in not actually being debt, but instead a 25 year lease followed by a purchase below actual value. It's the same thing in many ways - you pay an amount per month and get it at the end - the difference being (a) that you don't gain equity - you own nothing until that final payment, (b) you aren't paying interest as such but a lease fee, which it's why it's OK for Muslims, but in this case most importantly (c) it doesn't go on the books as borrowing.

Would be interesting to see if it works out dearer or cheaper than buying outright to begin with

 

[hwl]

Would be interesting to see if it works out dearer or cheaper than buying outright to begin with

We will have to wait a while to see as I suspect the big difference will be engineering and refurbishment expertise for the 25-40 year mark.

 

[hexagon789]

We will have to wait a while to see as I suspect the big difference will be engineering and refurbishment expertise for the 25-40 year mark.

Very possibly, though with there being so many Desiro-type units about might not that help with parts etc.

 

[Tetchytyke]

They are tapered so if any more of the Scotrail network were to be electrified, they could be used on routes with a narrower loading gauge

How does this work? I thought the loading gauge was based on the widest point of the train? So if the train is wider at the solebar than at the cantrail it won't affect the loading gauge, unless it is designed to tilt (which the 380s aren't)?

 

[RailWonderer]

How does this work? I thought the loading gauge was based on the widest point of the train? So if the train is wider at the solebar than at the cantrail it won't affect the loading gauge, unless it is designed to tilt (which the 380s aren't)?

They aren’t, but they resemble tilting stock. This photo shows the body line well.
The area that would be the sole bar is wider than the above area. The platform always lies below the tapered side.

 

[snookertam]

I think the aim was to maximise the internal space for seating within the train, whilst also maximising aerodynamics so they would be as energy efficient as possible. I'm pretty sure this was what Transport Scotland and ScotRail said at the time. Like the 385s, the 380s were based on a common design, the Seimens Desiro, but were altered to suit specifications laid out by Transport Scotland, hence the sloped front ends and retracting gangways. And the tapered bodysides.

 

[AM9]

How does this work? I thought the loading gauge was based on the widest point of the train? So if the train is wider at the solebar than at the cantrail it won't affect the loading gauge, unless it is designed to tilt (which the 380s aren't)?

That would be true if:

A) all track didn't have any can't on curves
B) if track has curves (as it does), that every overbridge, tunnel and structure matched the cant, I.e. vertical was perpendicular to the canted track datum, which they certainly aren't. Bear in mind that the sides of trains can't be perfectly vertical as there is more sway at cantrail than at solebar level.​

Don't forget, the profile of rolling stock has to fit into a dynamic (kinematic) envelope where all movement and track tolerances are allowed for.

 

[Mikey C]

It must have been expensive for Siemens to give the 380s a unique body profile for what was a relatively minor order