Class 22000 - Is it based on a common platform/design?

highdef

As per the title, the main reason I ask is if the 22000 class is bespoke design for Ireland, why were they made so narrow (9' 3", I believe)? I'm unsure what the maximum permissible width is but AFAIK it's at least 10'. Anyone know what the maximum width is allowed?

The same goes with regards to the widths chosen for other orders in the past, apart from the obvious British rail based MK II and III carriages which were a set size. When CIE built their own coaching stock in the 60's and prior, they often made carriages fairly wide, to take best advantage of the loading gauge. This was especially useful for suburban stock, as 3+2 seating could be installed and yet still have plenty of room for everyone and maintain a centre aisle with proportions that were not too restrictive.

The railways in some Scandinavian countries have very generous loading gauges with rolling stock up to around 11' or so in width, despite track gauges that are narrower than Ireland. As we were one of the first countries to build railways, our loading gauge versus track gauge is not very favourable compared to most other countries around Europe, despite their track gauge being over a half foot narrower than here but it's a lot lot better than the British mainland. So, despite Ireland having a higher permissible rolling stock width than the UK, most/all of our current stock is comparable in width to stock in the UK mainland.

Jamie2k9

As per the title, the main reason I ask is if the 22000 class is bespoke design for Ireland, why were they made so narrow (9' 3", I believe)? I'm unsure what the maximum permissible width is but AFAIK it's at least 10'. Anyone know what the maximum width is allowed?

Not a smart answer but all rolling stock is bespoke, the client tells a manufacturer what they want and they are selected based on it. IE likely looked at DMUs mainly in UK and tweaked them for themselves.

As for them been narrow, probably went with the current size based on existing infrastructure i.e platform clearance. You are right Ireland's track gauge would allow wider trains.

goingnowhere

The width is a function of length. So the longer you go you need to go narrower, both the Mk4 and 22K are wider than UK stock by a good margin.

Continental gauge/Bern/UIC is massive in comparison and parts of Scandinavia is bigger again.

Don't confuse track gauge and loading gauge the two are quite different

csd

The same platform is used in metre-gauge Malaysia:

https://en.wikipedia.org/wiki/KTM_Class_91

/csd

csd

highdef wrote: »

As per the title, the main reason I ask is if the 22000 class is bespoke design for Ireland, why were they made so narrow (9' 3", I believe)? I'm unsure what the maximum permissible width is but AFAIK it's at least 10'. Anyone know what the maximum width is allowed?

The structure gauge is given in the IE network statement here - see page 61. It's a horrible low-resolution diagram, but for coaching stock the maximum width appears to be 2.9 metres (static) and 3.11 metres (dynamic, ie moving).

Certainly wider coaches have been used in the past - the Park Royal carriages were 3.1 metres wide. A Mark 3 is 2.74m wide and a 22000 is 2.84 metres.

/csd

tabbey

csd wrote: »

but for coaching stock the maximum width appears to be 2.9 metres (static) and 3.11 metres (dynamic, ie moving).

Certainly wider coaches have been used in the past - the Park Royal carriages were 3.1 metres wide. A Mark 3 is 2.74m wide and a 22000 is 2.84 metres.
/csd

Park Royal coaches were not full width at each end, although laminates were.

As coaches got longer, greater provision needs to be made for trains passing each other on sharp curves.

The main reason for the narrow coaches used now on Irish rail, is that it is no longer cost-effective to design and build a modern coach for the Irish loading gauge. Our network will never accomodate the larger vehicles used on the continent, never mind Scandinavia, Russia, North America or Australia.

Therefore they choose trains designed for Britain, where the loading gauge is a bit smaller than ours.

goingnowhere

Just for reference the UK Mk5 coach which is heavily based on the IE Mk4 is 10cm narrower to fit the UK requirements.

All stock purchased since the Mk3 fleet was designed specifically for Irish needs and was wider just like the Park Royals, so the ICR or Mk4 would have serious gauging issues in the UK beyond the core GWR routes which always were a bit wider due the broad gauge heritage, so the assumption we are just getting UK width as its a cost cutting measure is rubbish.

To get the ICR's fit the angle grinders took lumps out of a few platform edges to get the clearance required.

The last coaches built for Ireland (and only Ireland) which did not exploit the gauge were the Cravens which Cravens probably reused tooling from UK projects as they are dimensionally identical to the BR MK1 in primary dimensions

Basic rules
23m coach, 2.7-2.75m UK, 2.85m IE
20m coach, 2.9 UK, 3.0 IE

The Park Royal's strictly speaking are outside gauge per Irish Rail's current spec's as while they meet the static clearance they won't make the kinematic envelope, i.e. dynamic clearance as they will lean out beyond the limits.

highdef

Out of interest, what width are the Cravens? For some reason, I always thought they were 3m (9' 6"). And for some reason, I always think that DARTs are the same.