About Brunel

6. About Brunel • Donald Cardwell, a well known historian of technology has this to say about him: "In Britain, the great master of engineering publicity was the Anglo-Frenchman, Isambard Kingdom Brunel, creator of the Great Western Railway, bridge builder, revolutionary naval architect and versatile, sometimes misguided, inventor. Brunel's positive achievements and his successful propaganda on behalf of bold engineering enterprise outweighed his less happy enterprises such as the atmospheric railway and the seven foot railway gauge."

7. About Brunel • His father, Sir Marc Isambard Brunel (1769-1849) • Himself a famous engineer, of French parents • Sir Marc's father (IKB's grandfather) was on the wrong (Royalist) side in the 1789 French Revolution, and escaped France with his family (Marc would have been 20) • He took American citizenship and was chief engineer for the City of New York for six years • He then returned to Britain, and married Sophie Kingdom, whom he had known in France in earlier days - hence their son's second name • The project which brought him back to England was his invention of a better way to make blocks, so essential to the rigging of ships • His mechanical assembly line methods completely solved the Navy's problem

8. About Brunel • Young Isambard went to work in his father's small engineering office in England when he was seventeen or eighteen • By now his father was just recovering from a "bankruptcy“ • He had lost his money on another government contract, making army boots by an improved mechanical method • But then peace broke out! (Napoleonic War ended 1815), the army wouldn't pay for the 80,000 boots in inventory • His father's major project, and the one he is most famous for, was the construction of a tunnel under the River Thames – the first tunnel under navigable water ever built

9. About Brunel • Brunel senior's greatest invention was a tunneling shield • An 80 ton cast iron structure in twelve frames which could be jacked forward as the tunnel was dug • IKB was injured in a tunnel construction accident • He recuperated in the region around Bristol • It was here that he became involved with his own first major project - a Suspension Bridge on the Avon Gorge

10. Brunel’s Bridge over the Avon Gorge • Brunel said after his design was selected amongst many competitors: "...of all the wonderful feats I have performed, since I have been in this part of the world, I think yesterday I performed the most wonderful. I produced unanimity among 15 men who were all quarrelling about that most ticklish subject - taste."

11. Brunel’s Bridge over the Avon Gorge • He got the job, and began the construction, but only got so far as to put up the end piers in his lifetime • It was full of difficulties, mainly funding • It was a very turbulent time politically in Britain • There were riots in Bristol in 1831 concerning the "Reform Bill” • He never actually saw the bridge finished • It was completed in 1864, and is still in use, called the Clifton Suspension Bridge

12. Clifton Suspension Bridge

13. Brunel’s Quote • Brunel on contracts to the lowest bidder: "...You are holding out a premium to the man who will make you the most flattering promises. It is quite obvious that the man who has the least reputation at stake, or who has most to gain by temporary success, and least to lose by the consequences of disappointment, must be the winner in such a race."

14. GWR • Brunel was awarded a survey contract in railroad development, and went on to be the architect of the Great Western Railway • Overall GWR was a great success, though one innovation which did not work out was the gauge • He proposed 7 ft for better ride and stability • Bucked the current 4 ft 8.5 inch standard • There is no doubt that the broad gauge gave superior ride and stability, but it was fighting a standard • JMW Heuristic: Standards win, even when they are not the best • The GWR was built at the wider gauge but later replaced with the standard gage in 1892

15. Atmospheric Railway • Brunel's liking for new things got him into trouble when he advocated the installation of an atmospheric railway in South Devon • The system had been installed on a short line near London, and in Ireland • It had the great attraction of doing away with the locomotive with all its cost, smoke, noise, and dust, and potentially could deal with steeper gradients

16. Atmospheric Railway • The system consisted of a 38 cm (15 in) 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 5 km 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 as the train progressed, but closed airtight behind it • Materials were not up to it. The flap was made of leather and metal, with a lot of grease. Among other things, rats ate the leather, especially when seal oil was used for greasing!

17. Atmospheric Railway • Because of the air pipe, the system could only operate on clear lines; junctions had to be handled manually • This and other limitations would have been there in any case, even if the materials had not failed him • There’s lots more we could say here – but let’s return to bridges

18. Pedestrian Suspension Bridge at Hungerford

19. Pedestrian Bridge • Suspension toll bridge built in 1840’s by Brunel • One of the longest bridges in the world at the time • Incorporated landing piers for boats in its footings • Commercial flop • Some say because of the stink rising from the heavily polluted river • The “Great Stink” emptied the nearby House of Parliament around this time • In the 1860’s the railways came and Hungerford Market became Charing Crossing • A squat, ugly railway bridge by John Hawkshaw replaced the bridge, but reused the piers • The Thames was narrowed and sewers and tunnels were put in place to stop the stink

20. Bunel’s GWR Bridge over Slough Original drawing In 2000 (reconstructed)

21. Railway Bridge over the River Wye

22. Railway Bridge over the River Wye • At Chepstow during the building of the Great Western Railway (completed in 1852) • Needed to take two tracks of 7 foot gauge across a 600 ft gap • Wye has the 2nd highest tidal range in the world • Brunel originally intended a timber arched truss design, but admiralty insisted on a headroom of 50 ft with a width of 300 ft for sailing ships

23. Railway Bridge over the River Wye • The bridge is not symmetrical (unusual for Brunel) • On the Gloucester side there is a 120 ft limestone cliff • On the Monmouth side there is level washland • The cliff forms a natural end on one side • The other end is supported by cast iron piers which were sunk through soft ground until they hit a solid foundation, then filled with concrete

24. Railway Bridge over the River Wye • Brunel decided to use tubular construction as tubes are ideal to carry the stresses and weigh much less • The tube would hold apart the ends of "suspension chains" which would look after the tensile forces in a truss carrying the plate girder railway bridge below • Brunel argued that the tube would be stiff, and with the railway deck "strutted" and "trussed" to the tube, the excessive distortions, to which a suspension bridge is liable under the passage of concentrated load, would be avoided

25. Railway Bridge over the River Wye • Each 300 ft span depended upon a 9 ft tube of riveted wrought iron plates to resist the inward strain of the chains • Brunel built his tubes on the flat land behind the shore of the right bank of the river; they had to be raised more than 100 ft. and lifted clear of shipping within 12 hours

26. Railway Bridge over the River Wye • Brunel kept the weight as low as possible • The tubes were 9 ft in diameter, 312 ft long and weighed a mere 138 tons apiece, but were not self-supporting • Without the inward pull from the chains at each end, and the upward support of the posts or struts of the "trusses," the tubes could not be expected to carry their own deadweight • Temporary trusses were therefore used and tested

27. Railway Bridge over the River Wye • The secondary stresses caused by deforming of the truss were alarmingly high • In 1944 one of the plate girders in the land spans partially collapsed • For many years, all trains crossing Chepstow bridge were restricted to speed limits of 15 mph • Temporary repairs were made • Gradually, more extensive repairs were made, and by 1962, the bridge had changed completely, being rebuilt into an inverted box girder form

28. Royal Albert Bridge at Saltash

29. Royal Albert Bridge at Saltash • Brunels last and greatest bridge • Crosses the river Tamar at Saltash near Plymouth • Two spans of 139m/455ft and a central pier built on the rock, 24m/80ft above the high water mark • The bridge was opened in 1859, the year of Brunel’s death

31. Brunel the Naval Architect • Brunel was also a great shipbuilder • The Great Western • a wooden paddle vessel was the first steamship to provide regular transatlantic service • The Great Britain • an iron-hull steamship, was the first large vessel driven by a screw propeller • The Great Eastern • At 689 ft, more than 6 times the largest ship prior • Propelled by 6500 sq yds of sails, two paddles and a screw and was the first ship to utilize a double iron hull • Unexcelled in size for 40 years, the Great Eastern was not successful as a passenger ship, but achieved fame by laying the first successful transatlantic cable

32. 1st Bridge Found • In March, 2004 a surprise discovery was made on the Grand Union Canal at Paddington - Isambard Kingdom Brunel's earliest surviving iron bridge – discovered on the eve of its planned demolition (original Iron bridge later covered over in brick)

33. More on His Father • Isambard’s father’s tunnel boring machine

34. References • http://www.engr.mun.ca/~gpeters/5101brun.html • Historical Metallurgy Society, Spring 2004 Newsletter • http://web.ukonline.co.uk/b.gardner/brunel/kingbrun.html • www.theengineerguy.comTunnels (broadcast May 25, 2004)