Old CIE diesel class system

[hexagon789]

I've had a look on the forum for an answer but can't find anything specific, nor was Google or Wikipedia much help. 

So how exactly did the old letter system work? I know what became the 001 Class were originally "A", the 201s were "C" and all of 121, 141, 181 and the Sulzer 101s were "B" and various small diesels and shunters were lettered "D" through "G" and "K".

My two questions are really:

Firstly - were the letters purely to show power rating or were these actual 'Class' designations even given the large variety within the "B" designation.

Secondly - what was the power range of each letter?

 

Thanks.

Edited June 16, 2020 by hexagon789

[Old Blarney]

1 hour ago, hexagon789 said:

 

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

Might this page help you? Scroll down to the bottom of the page. Pictures of Locomotives  - Letter type - A, B,C,  and Class Type.  

 

 

 

Edited June 16, 2020 by Old Blarney

[hexagon789]

44 minutes ago, Old Blarney said:

 

Thanks Old Blarney, I did look at the Wiki page before posing my question - but it doesn't really explain exactly what each letter referred to only which letter each loco type was originally allocated.

To explain what I mean, in the pre-1968 British Rail system each loco was classified by power then by manufacturer. 

A Type 1 was 800-1000hp

A Type 2 was 1001-1499hp

A Type 3 was 1500-1999hp

A Type 4 was 2000-2999hp

A Type 5 was 3000hp and over

 

Effectively I'm looking to see what the horsepower range of each letter of the CIÉ system was. Was "A" 1200hp and over or 1,000hp and over? That sort of thing.

[jhb171achill]

Power output, yes, though I don’t have the details in front of me.

Thus, there were five types of “B” class: the original pair, B113 & B114; the B101, B121, B141 & B181 types.

With the 071s coming just a few years later, had the same system remained, they would have possible become a new class (H?) or they would have been a new type of ”A”.

Had the latter been the case, the 071s would have become the A71 class; same numbers, A71-A88.

The number system of 071 onwards virtually confirms this.

[Old Blarney]

I did read your comment re Wiki, but thought the page I linked may have been of some assistance to you.

Information from  " Locomotives and Rolling Stock of Coras Iompair Eireann and Northern Ireland Railways O. Doyle and S. Hirsch.

Original Class 1000 ( Number of Locomotives 02 -  Renumbered 113- 1114 - Original Power Units - Sulzer              - 950 hp gross

Original Class (A) Number of Locomotives 60 -  Renumbered 001- 060 - Original Power Units - Crossley HST V8 -1,200 hp gross

Converted 1968/1971 to GM Power units.

Original Class (C) Number of Locomotives 34 -  Renumbered 201 - 234 - Original Power Units - Crossley              -    500 hp gross

Converted 1969/1978. to GM Power units - *C233-234 fitted with Maybach engines in 1965. 

Original Class (B) Number of Locomotives 12 -  (Renumbered) 101- 112 - Original Power Units - Sulzer 6LDA 28       - 960 hp gross

Original Class (B) Number of Locomotives 15 -  (Renumbered) 121- 135 - Original Power Units - GM 567 CA8            - 950 hp gross

Original Class (B) Number of Locomotives 37 - ( Renumbered) 141- 177 - Original Power Units - GM 567 CA8            - 950 hp gross

Original Class (B) Number of Locomotives 12 -  (Renumbered) 181- 192 - Original Power Units - GM 645 E 8           - 1,100 hp gross

Original Class (071) Number of Locomotives 18 -                           071- 088 - Original Power Units - GM 645  E3            - 2,450 hp gross

Original Class (201) Number of Locomotives 34 -                            201- 234 Original Power Units  - GM 710G3B           - 3200 hp gross

I hope this information is of use to you.

White.

 

 

[hexagon789]

31 minutes ago, Old Blarney said:

I did read your comment re Wiki, but thought the page I linked may have been of some assistance to you.

Information from  " Locomotives and Rolling Stock of Coras Iompair Eireann and Northern Ireland Railways O. Doyle and S. Hirsch.

Original Class 1000 ( Number of Locomotives 02 -  Renumbered 113- 1114 - Original Power Units - Sulzer              - 950 hp gross

Original Class (A) Number of Locomotives 60 -  Renumbered 001- 060 - Original Power Units - Crossley HST V8 -1,200 hp gross

Converted 1968/1971 to GM Power units.

Original Class (C) Number of Locomotives 34 -  Renumbered 201 - 234 - Original Power Units - Crossley              -    500 hp gross

Converted 1969/1978. to GM Power units - *C233-234 fitted with Maybach engines in 1965. 

Original Class (B) Number of Locomotives 12 -  (Renumbered) 101- 112 - Original Power Units - Sulzer 6LDA 28       - 960 hp gross

Original Class (B) Number of Locomotives 15 -  (Renumbered) 121- 135 - Original Power Units - GM 567 CA8            - 950 hp gross

Original Class (B) Number of Locomotives 37 - ( Renumbered) 141- 177 - Original Power Units - GM 567 CA8            - 950 hp gross

Original Class (B) Number of Locomotives 12 -  (Renumbered) 181- 192 - Original Power Units - GM 645 E 8           - 1,100 hp gross

Original Class (071) Number of Locomotives 18 -                           071- 088 - Original Power Units - GM 645  E3            - 2,450 hp gross

Original Class (201) Number of Locomotives 34 -                            201- 234 Original Power Units  - GM 710G3B           - 3200 hp gross

I hope this information is of use to you.

White.

 

 

I appreciate the direction to Wikipedia, it just wasn't quite specific enough for me, but those figures does enable one to infer the approximate ranges, so thank you.

50 minutes ago, jhb171achill said:

Power output, yes, though I don’t have the details in front of me.

Thus, there were five types of “B” class: the original pair, B113 & B114; the B101, B121, B141 & B181 types.

With the 071s coming just a few years later, had the same system remained, they would have possible become a new class (H?) or they would have been a new type of ”A”.

Had the latter been the case, the 071s would have become the A71 class; same numbers, A71-A88.

The number system of 071 onwards virtually confirms this.

A Super "A" I think

Perhaps they could've used double "A", given the approximately double power compared to an 001!

[Mayner]

The class system was based on power output and use similar to the British Railways system.

A------------1200hp-High power main line mixed traffic.

B------------960hp  Medium power main line mixed traffic

C-----------550hp    Low power branch line mixed traffic

D-----------487hp    Heavy shunting and transfer locomotive.

E-----------400hp    Shunting, banking and branch line duties. (Diesel hydraulic)

F----       224hp?   Narrow gauge mixed traffic (Diesel Mechanical)

G----------130hp    Light shunting and branch line services (Diesel Mechanical)

K----------800         Heavy shunting locomotive (Diesel Hydraulic).

There is a rumor that it was originally intended to classify the EMD GL8 (B121) locos in the K rather than B Class power category.

Although of similar power to the Sulzers the GL8s had a lower tractive effort and were considerably lighter than the Sulzers, which would have been a disadvantage on heavier main line passenger and freight duties.

B101--------960hp-------------41,800lb----------75 tons

B121-------950hp-------------35,000lb----------64tons

 

Although the majority of main line diesels fitted into the BR Class 1 & 2 power classifications a number of the Ar Class were uprated to 1650hp for Heuston Tralee passenger services which would have taken them into the BR Class 3 power classification

[Railer]

To follow on to this, I believe that the power rating letter was in relation to other classes. Not the Type system used in the UK in relation to HP rating.

For example, if they kept the system going, when the 071s were introduced they would become the new A class. The 001s drop to B and so on.

[jhb171achill]

The original “A”s would have become the A001 class, with the new arrivals as the A071 class, same as you’d B101, B113, B121, B141 and B181 class.

[Garfield]

2 minutes ago, Railer said:

To follow on to this, I believe that the power rating letter was in relation to other classes. Not the Type system used in the UK in relation to HP rating.

For example, if they kept the system going, when the 071s were introduced they would become the new A class. The 001s drop to B and so on.

Can't say I ever recall hearing that theory. It was a power rating, with A being 1200hp+, so the MetroVick As would have remained As and the 071s would have been As, too, if the system had been retained. It's interesting to note that as the big GMs arrived around the same time as the transition to the new numbering system, they were placed into the same series as the MetroVicks (001-060 and 071-088), rather than being placed into another category altogether (e.g. 901). 

[Railer]

10 minutes ago, jhb171achill said:

The original “A”s would have become the A001 class, with the new arrivals as the A071 class, same as you’d B101, B113, B121, B141 and B181 class.

I was thinking along the lines of the C201s becoming the B201s after the GM packs were fitted. It does make more sense than re numbering the whole loco fleet.

[jhb171achill]

1 hour ago, Railer said:

I was thinking along the lines of the C201s becoming the B201s after the GM packs were fitted. It does make more sense than re numbering the whole loco fleet.

Got ya, yes. My reasoning was based on 071 onwards being logically the next in the “A” series.

[hexagon789]

7 hours ago, Mayner said:

The class system was based on power output and use similar to the British Railways system.

A------------1200hp-High power main line mixed traffic.

B------------960hp  Medium power main line mixed traffic

C-----------550hp    Low power branch line mixed traffic

D-----------487hp    Heavy shunting and transfer locomotive.

E-----------400hp    Shunting, banking and branch line duties. (Diesel hydraulic)

F----       224hp?   Narrow gauge mixed traffic (Diesel Mechanical)

G----------130hp    Light shunting and branch line services (Diesel Mechanical)

K----------800         Heavy shunting locomotive (Diesel Hydraulic).

There is a rumor that it was originally intended to classify the EMD GL8 (B121) locos in the K rather than B Class power category.

Although of similar power to the Sulzers the GL8s had a lower tractive effort and were considerably lighter than the Sulzers, which would have been a disadvantage on heavier main line passenger and freight duties.

B101--------960hp-------------41,800lb----------75 tons

B121-------950hp-------------35,000lb----------64tons

 

Although the majority of main line diesels fitted into the BR Class 1 & 2 power classifications a number of the Ar Class were uprated to 1650hp for Heuston Tralee passenger services which would have taken them into the BR Class 3 power classification

Thanks, that's much more like what I was looking for, don't suppose you have the actual ranges? 

 

If "A" was 1200hp+, would "B" then be 950-1199hp; "C" 550-949hp etc?

[DiveController]

On 6/23/2020 at 2:24 PM, hexagon789 said:

Thanks, that's much more like what I was looking for, don't suppose you have the actual ranges? 

 

If "A" was 1200hp+, would "B" then be 950-1199hp; "C" 550-949hp etc?

Correct.

 Only the As didn't have an upper range limit, anything above 1200ho was an A

I think John quoted the cutoffs above which a loco fell into that class unless it reached a higher one as in the case of the C201 class which were uprated to about 1100hp and hence became B201s

 

Edited June 24, 2020 by DiveController

[Mayner]

Barry Carse outlined the background of the CIE power planning system in his book the Irish Metrovick Diesels (Colourpoint 1996)

Class A-------------1200hp upwards------------ 1-100

Class B------------800-1100hp---------------------101-200

Class C----------- 500-750hp------------------------210-300

Class D----------- 487hp Shunters---------------301-400

Class E------------420ho Shunters----------------401-500

Class F------------224hp Narrowgauge---------501-600

Class G----------0-4-0 Shunters-------------------601-700

Its possible that CIE may not have considered a requirement for a higher powered loco in the early 1950s as a 1200-1300 hp may have been the practical limit in terms of power for a 6 axle diesel electric with wide route availability on the Irish railway system.

Weight was a significant issue with diesel electric in the early 1950s with establish builders struggling to design locos within the limits specified by CIE, GNR & UTA 

The B and C class power ratings are broadly in line with those envisaged for main line mixed traffic by the GNR and a joint GNR/UTA working group in the early 1950s.

The joint working group initially identified a locomotive within an 800-1000hp power range for main line passenger and mixed traffic work and a "light locomotive" capable of 35-40mph for tripm working and shunting, the GNR later refined this to 1000hp for express passenger and heavy goods work, 800hp Mixed Traffic and 400hp Shunting and Trip work.

Interestingly in its tender to the GN Metropolitan Vickers proposed the 1200hp Co Co it was building for CIER for the 1000hp category at £61,433 and C Class in the 400hp power category.  GM proposed  its standard 875hp export G8 A1A A1A £52,179 and Nohab proposed its (GM powered) 1310hp A1A A1A at £63,414

It looks like the Metrovick order was more tied up with currency exchange and improving Anglo-Irish relations than CIE achieving value for money.

Some of the Class C were re-classified as Class B but retained their original running numbers, beginning with C233 & 234 when they were rebuilt with Maybach 1200hp MD-650 engines in 1965 and 66 some of the rebuilt C Class were repainted directly into the Supertrain scheme following re-build and did not receive the Class B suffix.