Isambard Kingdom Brunel

[richard]

Yes Brunel was right that 7ft was safer, could carry bigger loads, and could run faster. However, many of those limits for 4ft 8in were still way off in the future.

7ft was also more expensive - bigger bridges, tunnels, larger curves, etc. The opposite of narrow gauge, where the main advantage was the lower cost.

[Italianfan88]

Talking about gauges, it has nothing to do with Mr. Brunel, but the Italian railways only adopted Stephenson's standard gauge effectively in the 1930s.

This is only half of a joke - before, the gauge used was a bit higher: 4ft 8 and 9/10 of an inch.
Then, experiments with two sets of tracks (one left as it was and the other narrowed it to effective 1435 mm) found that the latter performed better.

[kudu]

I guess it must have been a bit of a nightmare working trains over a mixed guage i.e. the standard guage in with the 7ft broad guage although the GWR done it for quite a while until the 1890s.

Mickey

Mixed gauge makes for some interesting trackwork. Just imagine Liverpool Street in its "Jazz" period laid out for mixed gauge. It was complex enough with just the one. I suppose there must be the odd picture somewhere of the London Victoria LCDR approaches in its mixed gauge days, but I've never seen one.

Kudu

[Mickey]

I guess it must have been a bit of a nightmare working trains over a mixed guage i.e. the standard guage in with the 7ft broad guage although the GWR done it for quite a while until the 1890s.

Mickey

Mixed gauge makes for some interesting trackwork. Just imagine Liverpool Street in its "Jazz" period laid out for mixed gauge. It was complex enough with just the one. I suppose there must be the odd picture somewhere of the London Victoria LCDR approaches in its mixed gauge days, but I've never seen one.

Kudu

Yeah it looked complicated at Paddington and at junctions along the GWR main line and was probably hard work to maintain by P.Way gangs?.

Mickey

[Hatfield Shed]

I'm glad his broad gauge never took off the locos would have looked terrible plus old Isa was to GWR for my liking.

But..... would the loading gauge been larger all around. If so just think what Gresley would have done with that!!

Funny enough i remember a railway bloke telling me nearly 40 years ago that 'they' i presume parliment made a mistake in adopting the 4ft-8 half inch 'standard guage' and that the 7ft broad guage would have been a much better gauge to have adopted to run trains at higher speeds on!!. I don't know if thats true or not??

Mickey

The whole Brunel thing, very interesting. First of all, his rep as a great pioneering engineer is totally secure: shield tunneling and iron steamships are a huge achievement portfolio that put him in the first rank of those who drove the Industrial Revolution forward.

But when it came to the railway, he had a problem. He very clearly was not the pioneer, the Stephensons in particular held the laurels in the concept of a steam powered railway system. But of course he needed to be perceived as a leader in the field to win the investment money, and so the only way was 'different'; and thus the disaster of his railway work.

Failure 1. No systems thinking: a standard gauge is the key to efficient interoperability of a railway system and the GWR had to abandon BG.
Failure 2. No ability to design locomotives, a Stephenson trained man had to be brought in.
Failure 3. Adoption of an impractical form of fixed plant traction resulting in steep gradients, it failed, and the gradients resulting were long term troublesome. (He didn't have the tech. Eventually fixed plant power generation of the electric is going to provide a solution, but the seminal enabling work of Maxwell, Hertz and Tesla among others is still to be done.)

His good choice in railway work was location. Had he built in the territory occupied by the 'Stephensons and coworkers' group, he would have little reputation. Seen it already, no leap forward. But by building on virgin ground, he looked like a miracle worker to the locals who had never seen the like. His claims for the broad gauge were totally unfounded. Speeds and loads much in excess of those he claimed necessitated the adoption of broad gauge for future development potential have completely falsified his claims. Brunel was actually a major boob when it came to railway engineering.

[Mickey]

An interesting post of yours Hatfield Shed.

Another 'problem' i guess was Brunel's 'Baulk Road' which doesn't appear to be much cop either by all acounts being of a 'to ridged' design and was prone to break up easily with his locos and there trains rolling along it unlike conventional p.way which by design and when layed has a certain amount of 'spring in it' to absorb the 'hammer blows' of trains passing over the metals!!.

Mickey

[Hatfield Shed]

Indeed Mickey, I was only outlining the major and indisputably deficient concepts of the Brunel railway.

Another strike against the broad gauge is the axle length it required. This was a stretch for a load bearing component of restricted size and mass with the materials science of the day. The Stephenson party had the evolved and developed experience in track and rolling stock design guiding their choices; whereas Brunel was attempting a leap beyond their practise, while lacking that background.

[Mickey]

Another excellent post of yours Hatfield Shed.

Anyway all in all Isambard Kingdom Brunel was a great victorian engineer working in his field of engineering with what he had and what he knew in his day and me not being an engineer i wouldn't like to make any more comments about his work cos i'm not qualified to do so but i guess at the time 'his' railway and locos and there trains worked (if not perfectly?) they did work.

I read yeaterday that there is actually a 'Broad Guage Society' that believe it or not actually pushes for the reintroduction of the 7ft broad guage in this country??. You would have thought some people would have better things to do with there free time??.


Mickey

[Italianfan88]

Forgive me if I am wrong (which may very well be), but weren't the gradients of the South Devon Railway an unavoidable factor, wheter the line had been built for regular steam-hauled trains, instead of fixed plants of the "atmospheric railway"? If that is the case, how can Brunel's fascination with that traction system be held responsible for such an inconvenience?

[Hatfield Shed]

Not remotely so. Lines have been constructed in far more severe topographies with less severe gradients. It all comes to a decision about how much is to be spent on the engineering of the route to minimise the gradients. The attempt at economy in route engineering by reduction in the required works enabled by the 'atmospheric' system was a complete error.

Again it reveals a weakness in Brunel's system thinking. All the advantages of greater speed and capacity he claimed for broad gauge as compared to standard gauge is negated by the fixed and low power potential for any given pipe diameter using a vacuum system to transmit power to the train. The greatest power available is the piston area defined by the tube diameter, and whatever pressure differential is available between the pipe exhaustion and atmospheric pressure. A miserable 1 bar of atmospheric pressure, less all the system losses, sets a finite and very low limit on the power available.

[richard]

I agree - it all comes down to cost.The atmospheric railway was an attempt to do it cheaper, and it failed.

Brunel did better with his timber bridges. They were built for a tight budget and hence had a limited life. They've all been replaced or demolished (well I've seen piers in South Devon, so partially demolished ) - but after the original financiers and Brunel were long dead!

[Italianfan88]

I see, I did not know that these gradients were a consequence of Brunel's choice about the atmospheric railway. I stand corrected.

[Hatfield Shed]

It's a very interesting phenomenon even now, the hagiogaphy of IKB in the UK with respect to the railway. That he and those who followed him were champions at public promotion is in no doubt.

But looked at objectively his contribution - purely in terms of railway route built with no question of the quality or otherwise of the work - is minor. The majority of the UK network was built by the Stephenson team and their followers. These same people were the engineering consultants to all the early railway start ups in continental Europe. It's a huge achievement, and barely celebrated in the UK; they just got on with the job without undue fanfare.

[StevieG]

Without being an avid IKB fan, nor supporting any claim that 7-foot + 1/4 inch would've been a better standard in all respects, nevertheless its better stability was surely demonstrated by the head-on collision in ancient days (1860s - 80s) at Norton Fitzwarren, where IIRC, both trains stayed 'on the road' (and possibly both locos also did, or at least remained upright).

[Hatfield Shed]

Norton Fitzwarren 1890 was a moving BG train, striking a stationary standard gauge goods train. In these circumstances the kinetic energy of the moving train will act to keep it on the road, unless the wreckage it is accelerating ahead of it meets a seriously fixed obstacle like a bridge abutment or similar, to form a stop block which then deflects the moving train off the road.

In the most important matter though the claimed 'better stability' was of no help at all. Forty percent of those on the BG train were casualties, the typical outcome of high speed collisions without a subsequent fire in the days of fairly light wooden rolling stock.