Discussion in 'Diesel & Electric Traction' started by 34007, Jun 17, 2009.
What is the stronger class locomotive? Free Discussion....
How would you define 'strength?'
In basic figures:
Power output Engine: 1,550 bhp (1,156 kW)
Tractive effort: 45,000 lbf (200 kN)
Power output Engine: originally 2,750 bhp (2,050 kW), later derated to 2,580 bhp (1,920 kW)
Tractive effort Maximum: 55,000 lbf (245 kN) to 60,000 lbf (267 kN)
47 was derated because, as it turned out, they were so powerful that they were rotating the earth underneath them and as such often arrived up to 2 days early.
\/ Wasn't that just the SP ones?? \/
Both engines were designed to do completely different things
so its an unfair comparrison
33 is, surprise surprise, a Type 3 and a 47 is a Type 4.
Answer is in the numbering.
SO 47 - Type 4 Class loco? But then which was the stronger class that hardly failed? Then the type of class that was allowed to pass certain lines and then those which werent because of tthe sound barrier? Tonbridge for example?
What? Would personally recommend you stick to steam.....
You can't really look at it like that. 33s were useful at what they did, and 47s were useful at what they did. Both are still 'out there' and were/are sucessful, but they're so incomparable you can't really say 'which is better'. It's like comparing a Black Five with an Austerity - both lasted around the same time, were good at what they did.....but like chalk and cheese technically.
Not being disrespectful. But as ive driven both types of traction, in all scenarios..ie freight and passenger. I would much prefer a 47 for pulling power. Maybe, you were my Guard once on BR?
Myself too - 47's can do anything. They always seemed the stronger class of loco.
Except on Waterloo-Exeter duties were they were in fact less reliable than the class 50`s they replaced. Even 33`s on the occasional Waterloo-Exeter were regarded as more reliable. And to hear a pair of 33`s on the Meldon stone, up the bank from Exeter St Davids to Central was a sound to remember.
The 47s provided for this service were hardly in the first flush of youth.
The 47s provided for this service were hardly in the first flush of youth.[/quote:9aeu5n1p]
I guess ask the drivers of the Waterloo to Exeter runs - 33's on w'loo - Exeter....
Yep 50's pre-vailed on those runs, but this is about the 33's Vs 47's....
33s do seem to be a nice sized diesel for most preserved lines, 47s are rather intimidating and can dwarf most things! (50s are bigger still!)
Having said that though, personal preference is for the 47.
It's the sherman tank to the 33's stuart...
Not really a fair comparison in this.
The 33 is fitted with a 8LDA28 engine previously used in the boats built for service on Swiss lakes such as Lake Lucerne and adapted for rail use to meet the Class 33 specification at the end of the 1950s.
The 47 is fitted with the 12LDA28C engine which was uprated from the earlier 12LDA28B engine fitted to the Class 45 / 46s and themselves uprated from the 12LDA28A engine fitted to the Class 44s. The original engine was IIRC used in submarines and may have been part of the reason why British engines ( both B and C series ) were built under licence by Vickers - a submarine builder - when the engines were built in Britain under licence.
The history of both engines would suggest which is best; the Class 33s governed by the SR to 85 mph and operated reliably on a variety of duties and reckoned by SR men to be the best. Certainly the coupling of the Sulzer engine with Crompton Parkinson equipment specifically designed to work with Sulzer engines from the earliest days of BR diesels helped the reliability factor but the 33 remains a workhorse par excellence.
The Class 47s fitted with an engine ( C series ) which even Sulzer admitted was an "uprating too far" and had to be downrated to 2580 hp for the rest of their working lives; coupled with Brush electrical equipment which was a poor substitute for the Crompton Parkinson equipment of the Class 33s their reliability was always under question.
It was only the large numbers of Class 47s which were available that hid the poor reliability - or the amount of engineering maintenance - which kept the brutes on the road. On a good day they were good but on a bad day - !!!!
I can remember riding in the cab of 47514 / D1960 and noting that speed plateaued at 85 mph before slowly increasing to reach a max of 100 mph but the performances of the class was so unpredictable that few drivers looked forward to having charge of then in my experiences during the 1970s.
Was that on a dead level track or did you take into account important factors such as gradients ?
It was on the MML racing track between Luton and Bedford - slightly downhill IIRC; just to further inform, load was 9 x MkI working 1P22 - 17:26 St Pancras - Derby. Given the same load and train the Class 45s - with the B series engine and Crompton Parkinson electrical equipment - regularly used to be coasting in the upper 90s / low 100s by this point
The 47s provided for this service were hardly in the first flush of youth.[/quote:1r30f8cr]
And neither were the 33s!
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