Historic Linespeeds on Irish railways.

[hexagon789]

I was discussing Maedh with a friend and how she managed I think it was 96mph and sister Tailté 95mph and I mentioned that the linespeed on the Dublin-Cork was 70mph in the post-war period and that together with coal shortages and subsequent dieselisation meant the 800s never really got a chance to show their true potential as such.

 

Anyway, he commented that it was strange that the GSR imposed a 70mph limit when their locos could do 95, and I said well the 70 limit came first surely, then I recalled an article about Ireland's early diesels which gave some mention of the sort of timings one had in the '50s and I noticed this sentence:

 

"The Dublin-Cork double track mainline, 165.3 miles long, and which, although well engineered, in the post-war period had an overall 70 mph speed limit imposed."

 

Maybe I'm over-reading it but the word 'imposed' suggests it may once gave been higher?

 

So to my point - was the limit on the Dublin-Cork higher than 70 pre-war, and if so what was it? I'm thinking 75 possibly 80, my friend thought 90 but I think that's too high.

Of course when one starts with one simple question, it quickly morphs into a whole heap of questions and so I'd be very grateful if someone could answer any of the following:

1. The maximum on the Dublin-Cork pre-war

2. When and why it was raised to 75

3. When it was raised to 90

4. When it was raised to 100 (I believe May 1995 but I cannot find where I got that date from)

5. Were the Mk2Ds ever permitted higher than 75? The Harris book on Mark 2 coaches suggests they were introduced running at 80mph on Dublin-Cork on a 2.5 hour timing, I don't know whether this was simply the plan or if it actually happened.

6. The actual service maximum for a 121, I've seen 77mph quoted by some sources, 75 by others. 75 seems logical to me, 77 more liked the maximum the gearing will allow.

7. The actual service maximum for a 141, I've seen 75, 76 and 80

8. The actual service maximum for a 181, I've seen 75 and 80 service as well as a design maximum of 89?

9. The maximum for a 001 'A' Class, books suggest 75 for all originally biut some had the traction motors rewound and were uprated to 80mph for the 'Enterprise'? I thought that the Mk2 stock and indeed the Dublin-Belfast mainline was 70 maximum until the De-Dietrichs were introduced in the early '90s.

10. I therefore assume that the 071s were unable to 'officially' run at 90 until the Mk3s were introduced and whenever the Dublin-Cork mainline was upgraded for 90mph running?

 

Thank you for you patience with this horrendously long-winded post and thanks for any replies.

Regards, Ben

 

[Mayner]

I don't know if there are verified 90+ mph timings for members of the  800 Class or other Irish steam locos.

Irish steam records are mainly based on stopwatch recordings of runs by journalists and enthusiast "timers".

In the steam era there was little need for high speed running in the absence of competing routes apart from Belfast-Londonderry and Belfast-Newcastle, in the South average train speeds were scheduled with relatively low 42.3mph Kingsbridge-Cork, 26.9 mph Kingsbridge Waterford, 33.6mph Broadstone-Galway. The most important trains were the cross-Channel Mails which were heavily loaded and called at all the principal stations, the ordinary all-stations passenger trains were even slower.

The Irish steam record is held by  a 1934 non-stop Dublin-Cork special (for the newly appointed American Ambassador) with a recorded average speed of 85.6 mph between Ballybrophy and Portlaoise. 402 may have reached or exceeded 90 at some stage between the two stations.  Cecil J. Allen a British railway journalist appears to have been invited by the GSR to record the run. average speed exceeded 70mph between Limerick Junction and Kingsbridge.

The loco was 402 a 2 cylinder 4-6-0 driven by Mark Foley with 3 coaches (95 tons gross). 402 was considered to be the best of the rebuilt 400 Class similar in capability to a GWR Saint or Southern King Arthur.

800 is reported to have achieved 92mph during a demonstration run in July 1939

There is a log of a run of 800 on an up Cork Mail between Portlaoise and Kingsbridge  in Aug 1939 with 450 Tons in O.S. Nocks Irish Steam with a maximum recorded speed of 76.5 mph at Hazlehatch. O S Nock was particularly impressed with 800s acceleration on the climb out of Cork but the crew ran into problems with a sticking regulator valve near the top of the bank out of Cork and a patch of poor quality coal during the middle of the journey.

A number of 001 Class were uprated to 1650hp this was to ensure that certain trains including Heuston-Tralee passenger trains could keep time within the existing line limits of 70mph on the Dublin-Cork line and 60mph Mallow-Tralee lines.

 

[hexagon789]

On 1/2/2019 at 11:44 PM, Mayner said:

I don't know if there are verified 90+ mph timings for members of the  800 Class or other Irish steam locos.

Irish steam records are mainly based on stopwatch recordings of runs by journalists and enthusiast "timers".

In the steam era there was little need for high speed running in the absence of competing routes apart from Belfast-Londonderry and Belfast-Newcastle, in the South average train speeds were scheduled with relatively low 42.3mph Kingsbridge-Cork, 26.9 mph Kingsbridge Waterford, 33.6mph Broadstone-Galway. The most important trains were the cross-Channel Mails which were heavily loaded and called at all the principal stations, the ordinary all-stations passenger trains were even slower.

The Irish steam record is held by  a 1934 non-stop Dublin-Cork special (for the newly appointed American Ambassador) with a recorded average speed of 85.6 mph between Ballybrophy and Portlaoise. 402 may have reached or exceeded 90 at some stage between the two stations.  Cecil J. Allen a British railway journalist appears to have been invited by the GSR to record the run. average speed exceeded 70mph between Limerick Junction and Kingsbridge.

The loco was 402 a 2 cylinder 4-6-0 driven by Mark Foley with 3 coaches (95 tons gross). 402 was considered to be the best of the rebuilt 400 Class similar in capability to a GWR Saint or Southern King Arthur.

800 is reported to have achieved 92mph during a demonstration run in July 1939

There is a log of a run of 800 on an up Cork Mail between Portlaoise and Kingsbridge  in Aug 1939 with 450 Tons in O.S. Nocks Irish Steam with a maximum recorded speed of 76.5 mph at Hazlehatch. O S Nock was particularly impressed with 800s acceleration on the climb out of Cork but the crew ran into problems with a sticking regulator valve near the top of the bank out of Cork and a patch of poor quality coal during the middle of the journey.

A number of 001 Class were uprated to 1650hp this was to ensure that certain trains including Heuston-Tralee passenger trains could keep time within the existing line limits of 70mph on the Dublin-Cork line and 60mph Mallow-Tralee lines.

 

Thank you for the reply, interesting to read that it wasn't only the '800s' capable of higher speeds.

 

I can understand the uprating of the 001s for that reason then.

 

Does this also mean that Dublin-Cork was never higher than 70 pre-war then?

[jhb171achill]

Anecdotes exist, timing the 800s at 100 or therebouts.

My father travelled with his father on several trial runs of 800 itself in 1939. It was timed at just under 100 mph, but the crew said that bar a signal check or some other obstruction (the details of which I can't remember) they would have got more out of her. Correctly or otherwise, the opinion of crews was that they were well capable of 100 and a bit more.

The "timing" fraternity of railway enthusiasts timed many a run at 80mph +, but as you say there was a line speed limit, which had more to do with track maintenance budgets and timetable paths (some trains were very slow!) than the performance capabilities of the 400s, 500s, Woolwiches and 800s.

Actually, early speed trials of the 800 class WERE a lot more accurate than the whims of timers and enthusiasts. They had speedometers - the first ever in the Irish steam world. Since nothing else had them, they were eventually removed.

[hexagon789]

On 1/10/2019 at 12:08 AM, jhb171achill said:

Anecdotes exist, timing the 800s at 100 or therebouts.

My father travelled with his father on several trial runs of 800 itself in 1939. It was timed at just under 100 mph, but the crew said that bar a signal check or some other obstruction (the details of which I can't remember) they would have got more out of her. Correctly or otherwise, the opinion of crews was that they were well capable of 100 and a bit more.

The "timing" fraternity of railway enthusiasts timed many a run at 80mph +, but as you say there was a line speed limit, which had more to do with track maintenance budgets and timetable paths (some trains were very slow!) than the performance capabilities of the 400s, 500s, Woolwiches and 800s.

Actually, early speed trials of the 800 class WERE a lot more accurate than the whims of timers and enthusiasts. They had speedometers - the first ever in the Irish steam world. Since nothing else had them, they were eventually removed.

Indeed, some appear to have been very slow. 

 

Interesting, are they still the only Class to have had speedometers or do locos operating on the mainline require them now?