Northern Ireland class numbers

[MK Tom]

I've been trying to make sense of NIR train class numbers and I can't... I was wondering if anyone could help me understand the numbering system, if there is one?

So originally there were the class 70 DEMUs. Then they were replaced by the class 80s. That's cool. So then the next DEMU class after that should be the class 90... but it's not. It's the class 450. But the class 111s are locomotives, so how come class 80 and class 450 are both DEMUs? So anyway, the next class after that should be 460... or 500... or...

3000!?!?!?

If there is a system that these classes are numbered by I'd be very interested to know it! It doesn't seem to bare any relation to TOPS and it has some similarities to the IE system but it's definitely not the same as that either. Does anyone have any ideas?

 

[Eagle]

I think it's just a case of "numbers that are easy to remember"...

 

[4SRKT]

NIR has no TOPS or equivalent. For locos (as with CIE/IR) the lowest number in the class became the class number, e.g. large GMs were numbered 071-088 by CIE and 111-113 by NIR and became 071 and 111 class respectively.

Something similar applied to DEMUs, with the 70 class numbered 71-78. The initial batch of 9 DEMUs based on the BR mk II bodyshell in 1974 were numbered 81-89 and correspondingly called '80 class'. The next batch of 13 units in 1977 was numbered 90-99 and 67-69, and this is why the 450 class could not be called '90 class'. A similar concept was used for the 450 class, numbered 451-459.

After NIR, Ulsterbus and Citybus were grouped together as Translink, all NIR vehicles had 8000 added to their numbers so as to fit on the Ulsterbus computer system. Hence (for example) 450 class vehicles became 8451-8459. Railway folk don't call them this though, and stick to 451-459.

Classes introduced post-Translink such as the 3000 CAFs have to have 4 digit numbers to fit on the Ulsterbus computer. The new CAFs are 4000 class or 'C4K'.

 

[K9-70]

It would depend what number series was avaiable at the time when the Dmu/Demu's were built.

UTA Diesel Mechanical Multiple Units (DMMU)
Built 1951, Wdn 12/68
6 & 7

UTA MED (Multi-Engined Diesel Units)
Built 1952-53
8 - 35

UTA MPD (Multi-Purpose Diesel Multiple Units)
Built 1957-58
36 - 65

UTA 70 Class Diesel Electric Multiple Units (DEMU) Originally known as Hampshires))
Built 1966-68 (#78 built by NIR)
71 - 78

NIR/BREL 80 Class Diesel Electric Multiple Units (DEMU) 1st batch
Built 1974-78
81 - 89 1st batch
90 - 99 and 67 - 69, 2nd batch 90 Class Diesel Electric Multiple Units (DEMU)
The second batch was to become the 90 Class, but due to minor detail differences between
the 1st & 2nd batch they were reclassified as 80 Class.
#88 involved in accident at Hilden, Wdn 25-03-1983, engine to Castle Class #457


NIR/BREL Castle Class (later 450 Class Diesel Electric Multiple Units DEMU)
Built 1985-87 to the BR Class 455 design but using withdrawn Mk1 BSK chassis's and the 70/80 Class engines.
451 - 459
It should also be noted that the BR Class 150/1 & 150/2 are of similar design to the NIR Castle Class 450's.

 

[GM078]

Would the numbers "between" the GMs and the 450s have been taken up by carriages? 450 is a good bit out from the rest, strange how similar it is to the BR class 455s considering the similarities between the two.

 

[4SRKT]

DEMU trailers were numbered in the 700s, loco hauled carriages for the Hunslet sets in the 800s, and the GM-hauled Enterprise stock in the 900s, so no.

 

[GM078]

DEMU trailers were numbered in the 700s, loco hauled carriages for the Hunslet sets in the 800s, and the GM-hauled Enterprise stock in the 900s, so no.

Thanks. Anyone know why they specifically went for "450"? It was hardly because they were similar to the BR 455s? Assuming they wanted to keep the "1xx" sequence for locos could they have not gone for a sequence in the "200s" (considering NIR would not get GM 201 class locos for another decade or so)? I always thought "450" seemed a bit random compared to their other MUs and locomotives.

 

[4SRKT]

Thanks. Anyone know why they specifically went for "450"? It was hardly because they were similar to the BR 455s? Assuming they wanted to keep the "1xx" sequence for locos could they have not gone for a sequence in the "200s" (considering NIR would not get GM 201 class locos for another decade or so)? I always thought "450" seemed a bit random compared to their other MUs and locomotives.

As an aside NIR did of course get 6 201 class locos in the 1980s in the shape of 6 redundant Bo-Bo Metrovick C class locos from CIE. Not that NIR kept those numbers, instead numbering them 104-109 running on from the 101-103 number sequence of the Hunslets. I remember these engines in NIR blue out and about on ballast trains. They looked a hell of a lot better in CIE black and orange though......

And for completeness let's not forget the 3 Dorman engined 0-6-0 diesel hydraulic locos bought by NIR in 1969, numbered 1, 2 and 3. Had haulage of at least one of these having been in the stock of the Portrush Flyer being shunt released at Belfast York Road several times

I haven't a clue about why 450 was chosen as the class number. It's so random that I wouldn't be in the slightest surprised to learn that it was in fact because they had 455 bodyshells.

 

[K9-70]

I haven't a clue about why 450 was chosen as the class number. It's so random that I wouldn't be in the slightest surprised to learn that it was in fact because they had 455 bodyshells.

The 450, 781, & 791 number series was the only number series free at the time when the Castle Class (450 Class) was built. The rest of the number series where taken up by the various GNRI, UTA, Dmu/Demu's, coaching stock as well as goods wagons.
Most of the coaching stock and goods wagons had been withdrawn and scrapped by the time the Castle Class entered service, but for some reason or another these fleet numbers still remained on the books and therefore couldn't be used. It is around 15 to 20 years before a previous number series can be reused again.

 

[GM078]

The 450, 781, & 791 number series was the only number series free at the time when the Castle Class (450 Class) was built. The rest of the number series where taken up by the various GNRI, UTA, Dmu/Demu's, coaching stock as well as goods wagons.
Most of the coaching stock and goods wagons had been withdrawn and scrapped by the time the Castle Class entered service, but for some reason or another these fleet numbers still remained on the books and therefore couldn't be used. It is around 15 to 20 years before a previous number series can be reused again.

Interesting information. I know the UTA had coaches in the 200 sequence as the RPSI mkIIs are numbered from there on (300 onwards). I didn't realise they had to wait that long to reuse a number.