Brunel’s Railways

Today, we rather take railways for granted, noticing them most when they go wrong. They seem like part of the landscape, and it requires an effort of imagination to grasp what a vast cultural and economic achievement they represented when they were new, and what they meant to the people who built them.

While Brunel was still in Bristol, and with the Avon Bridge project stopped or going slowly, he became aware that the civic authorities saw the need for a railway link to London.

Railway location was controversial, since private landowners and towns had to be dealt with. Mainly, the landed gentry did not want a messy, noisy railway anywhere near them. The Duke of Wellington (of Waterloo fame) was certainly against it; he is reported to have said,

“... it will only encourage the lower classes to move about...”

Again Brunel showed great skill in presenting his arguments to the various committees and individuals. A person observing his performance in hearings in the House of Lords described him as,

“... rapid in thought, clear in his language, and [he] never said too much, or lost his presence of mind.”

Atmospheric railway

Brunel built his railway with a broad gauge (7ft) instead of the standard 4ft 8½in, which had been used for lines already installed. There is no doubt that the broad gauge gave superior ride and stability, but it was fighting a standard. In this he was also up against his professional rival (but personal friend) Robert Stephenson and Robert’s father, George Stephenson. After much argument, the government settled the matter in 1846 by requiring any new lines to be standard gauge.

Brunel’s ready acceptance of new ideas overpowered good engineering judgement (at least in hindsight) when he advocated the installation of an “atmospheric railway” in South Devon. It had the great attraction of doing away with the locomotive, and potentially could deal with steeper gradients.

The system consisted of a 15in-diameter pipe, laid between the rail lines, with a slit cut along the top. A piston fitted into the pipe, and was connected to the driving railcar above by an arm. The pipe ahead of the piston was then evacuated of air by pumps stationed about two miles apart along the line. The atmospheric pressure then drove the train.

Since this connecting arm had to run along the slit, it had to be opened through a flap as the train progressed, but closed airtight behind it. Materials were not up to it, and this arrangement was troublesome and expensive to keep in repair. After a year of frustration, the system was abandoned. Brunel admitted his failure and took responsibility. He also took no fee for his work, setting a good professional example.