The rock being very hard, the bridge was designed to fit the profile of the gorge with as little expenditure on excavation as possible; and it would have done so, but for a mistake made by the surveyor in concluding that the rock on both sides was solid. The mistake was perhaps excusable, and was not discovered until the vegetation which thrives in the hot sun and the spray from the falls had been removed, and the work of clearing the ground and the excavation of the rock had proceeded for some time. It was then found that the shelf on the right bank on which it was intended to rest one end of the principal span was covered to a considerable depth with debris. By the time the error had been discovered, the preparation of the steelwork was too far advanced to permit of any alteration being made in the structure. The difficulty had therefore to be overcome partly by increasing the depth of the concrete foundations, and partly by lowering the level of the entire bridge to the extent of 21 ft.; but both time and money would have been saved had the true facts of the case been recognised at the beginning, the span designed 25 feet longer, and the truss increased in depth at the ends by 20 ft.
Once work got under way, two parties were assembled, one on each side of the gorge, and their first job was to establish communication by telephone. The first attempt involved attaching a line to a kite and letting the wind carry it over. The kite was raised, released and proceeded to dance very prettily in the eddies, but refused to go anywhere near the opposite bank. After that a rocket was fired across, which worked perfectly, and a marked wire was used to check the surveyors’ measurements of the width of the gorge. This was followed by a cableway which was to be the main transport system until the bridge itself was complete. One of the young engineers working on site was a member of the Fox family, C. Beresford Fox, who described the excitement of the first gorge crossing in a letter home, dated 21 November 1903.
Well, I am crossing the gorge almost daily now by the wire rope: it is such a saving of time and trouble; but the first sensation is almost terrific. I was the first to cross, and did so from the north to the south side. The cable is a ⅝-in. diameter steel wire rope, 900 ft. in length, and is supported at each side by a solid post 2 ft. in diameter, let down into the rock some 7 or 8 ft. Then a ¼-in. stranded wire acts as an endless hauling rope round a windlass at one side and a pulley on the other.
The running pulley is, however, not quite satisfactory, as we could not obtain a trolley in Bulawayo, and so, temporarily, have to do the best we can; the present arrangement is safe, but not good mechanically.
An entertaining poster advertising the railway as a way of enjoying Africa’s wildlife.
As they tied me into the ‘bosun’s chair’ I must admit to feeling a bit strange in relying absolutely on my own calculations for my safety. The chair is a piece of wood suspended by four ropes, with a canvas back and a sack and board as a foot rest. Of course one is so tied in that were you to lose consciousness you could not fall out; this precaution, for some people, is advisable.
All ready, so they gave the signal to the windlass on the south side, and I felt the endless rope tightening and pulling up the slack, and slowly out the pulley ran.
The precipice is so steep on the north side that after five yards of one’s journey you are hanging over a 100-ft. depth. and after thirty yards over the rushing water 400 ft. below – more than the height of St. Paul’s Cathedral. It was a novel experience and one well worth feeling, as the eye finds it so difficult to give a correct impression of the height – the stereoscopic effect is not great enough in looking downwards (a most unusual direction); but as the ‘boys’ working at the bridge hurled down huge boulders and stones I then noticed that the long time taken for these to reach the water below me was much more startling than when seen from the opposite side. No downward motion can be discerned, only the dwindling of the rock in size, due to the perspective effect, as it falls lower and lower before reaching the water with a report like blasting and a splash more than 50 ft. in height. I found myself quite relieved when directly over the water, with no prospect of falling on to a rock in the event of the rope breaking.
Two of the famous man-eating lions of Tsavo shot by Lt. Col. Patterson: they were stuffed and put n display in a local museum
After the first few moments there is a real charm in looking down; nothing but space between you and the water, save for the ‘sag’ of the returning endless wire; the small trees and even the large ones on the south ledge bearing such a different appearance below.
Of course the predominant thought is, what would one feel if the pulley broke, whether you would really be unconscious after the first 100 ft., and whether the last jerk you felt isn’t the cable snapping; and you hurriedly look down to see if the water and rocks are not rushing up to meet you in your downward flight, and are relieved to see the cable still intact and stretching in a graceful curve to either side of the gorge.
Such a comfortable sensation too, on a sagging rope – a smooth, gliding motion, and but for the slight vibration caused by the pulley running over the separate strands, more like that of a boat, with a steady rise and fall, and perhaps a slight swinging of the chair from side to side.
This journey of 300 yds. through the air saves a detour of 9 to 10 miles by land and river, and gives a good idea of the splendid view which will be obtained from the bridge, when completed, of the superb scenery.
The early work was also exciting in a different way.
Excavation for bridge is getting on slowly only, owing to the impossibility of getting ‘boys’; there is also such a great deal of cleaning down of the sides of the cliff, to get rid of loose boulders, that the work has been increased in amount. Of course on the north side the debris you clear away falls into the water below, but on this side it falls 80 ft. and then rolls, and will mostly have to be shifted again, unavoidably too, owing to the ledge of rock.
What erratic courses falling boulders take! You start a large one from the top – probably it breaks, and the pieces go in all directions within 45° of its original course; but often the whole boulder on landing takes an entirely new route, and goes crashing through the brushwood beyond the 60-ft. clearing, and away over the ledge at least 100 ft. to the right or left of where it started.
He also had more mundane matters to deal with.
I am putting up some fifteen or twenty huts for the railway company, or for the men and boys, e.g. a bedroom hut (all circular), 13 ft. or 14 ft. diameter inside, about 7 ft. or 8 ft. walls, and a sloping conical roof another 12 ft. high. It is made of poles cut out of the bush, and placed close together all round save for doors or windows. The roof is then thatched with good grass, and the walls and floors ‘dargha’d’, i.e. plastered with clay hiding the poles completely; and then you have a delightfully cool and waterproof dwelling.
The workers had a number of problems to cope with. Cecil Rhodes had the romantic notion of passengers looking at the falls through spray-lashed windows; it perhaps never occurred to him that this inevitably also meant spray-lashed construction gangs. However, the work went steadily forward, as the cantilevers were steadily advanced from either side, until the two halves of the arch met with perfect precision on 1 April 1905 – and there was no unexpected April Fool’s Day disaster to mar the occasion.
While the bridge was still being built, the line was being continued northwards, at some speed, as a French engineer was to discover. He asked the chief engineer, Sir Charles Metcalfe, how much track could be laid in a day. Sir Charles in his turn asked him to make a guess, and the Frenchman came up with an estimate of half a mile. Sir Charles had a word with the assistant engineer, the engineer spoke to the foreman and the foreman spoke to the gang. A whistle was blown and work began. When a quarter of a mile of track was complete, the whistle was blown again and the stop watch consulted. Twenty minutes had passed from start to finish. It seemed unlikely that a pace like that could be kept up for long, but Sir Charles was intrigued to find out just how much track could be laid in one day. They managed 5 3/4 m
iles. Americans had recently begun using the latest automatic track-laying machines. In the same period, they could only set down four and a half.
The line pushed steadily north, held up less by engineering problems than by financial. There was a long stop at Broken Hill, but by November 1909 the line that had started at the Cape now extended all the way to the border with the Belgian Congo. Although the main line received most of the attention it was not the only route being built in the region. One line was intended as part of a system that would link the coast, not this time to Salisbury but to Lake Nyasa. The starting point was to be Port Herald on the Shire River, a tributary of the Zambesi. From here the line would head north for over a hundred miles to Blantyre, with the possibility of a later extension to the lake itself being kept in mind. It stands as a classic case of the follies that can occur when bureaucrats in London impose conditions on the engineers in the field – conditions which have everything to do with politics and nothing to do with practical solutions to practical problems.
The original plan had called for a line that would start at Chiromo, some 30 miles north of Port Herald, but the river was so treacherous with shallows and constantly shifting sandbanks that it was decided that no river craft would ever reach there –hence the extra rail mileage to Port Herald. Chiromo was, however, to be the place where the railway crossed the river on a substantial bridge, over 400 feet long. At least, the engineers felt, there was one thing on which everyone was agreed – there would be no river traffic. That was certain. They had not made allowances for the Whitehall mentality. There was certainly no chance of river traffic now, but what if circumstances changed. Exactly what circumstances might change to make this wholly unnavigable river usable by anything larger than a canoe was never explained. Nevertheless it was insisted that the bridge would have to be pierced with a centre span 100 feet wide, giving a head room above high water of 30 feet. It was wholly impractical to build to that height, so either a lift or swing bridge was needed. The conventional swing and drawbridge were of no use, when only manual labour was available, so ingenuity was exercised in building a new type of lift bridge. Towers were built at either side of the statutory 100 feet gap with large cogs at the top. Chains passed over the cogs with the span at one end and counterweights at the other. Mechanical force only had to overcome friction, though for a structure of that size that was bad enough. It took eight men winding the windlass for half an hour to raise the bridge. The parts were made in Britain, shipped out to Africa and erected. At this point the fickle River Shire went through one of its periodic changes of direction. Sand built up under the new span and the main channel diverted itself to go under one of the fixed spans. The whole exercise had proved entirely futile. In time even Port Herald was to be left stranded and the line had to be extended even further south to the Zambesi itself. It was 1915 before the line eventually reached the lake. The lake itself was controlled, in 1914, by the Germans who had a gunboat to make sure it stayed that way. But at the outbreak of the war, a small force came up the railway, disabled the gunboat and claimed the lake; it is generally thought of as Britain’s first naval victory in the war, and was the inspiration for C.S. Forester’s novel, The African Queen.
Missionaries waiting for a train on the Uganda Railway.
Lines were pushed inland in a rather tentative way from various places along the west coast of Africa at the very end of the nineteenth century. The process began in Sierra Leone with a very grandiose promotion for what was called the Grand Sahara Railway. This was one of those lines that looked very pretty when drawn on a coloured map in London but was wholly impractical to anyone with even the slightest knowledge of northern Africa. It was soon dropped. After that a more systematic approach was adopted. Sir William Shelford was approached by the Crown Agent for the Colonies and asked to conduct a survey of possible railway routes along the West African coast. He decided to begin in Sierra Leone. He had no plans to visit the region himself, but appointed the engineering company of Bradford, Knights and Hayton. W. Bradford was the man who drew the short straw for a trip to the ‘fever coast’. In spite of the medical staff that was sent out and the field hospitals that were established, four of the European staff died from tropical diseases between November 1895 and April 1896. It did not seem from the map to be a very adventurous line, pushing just a few miles inland from Freetown to Songo, and even the long-term ambitions of a line to the Liberian frontier only represented a route of around 100 miles of narrow gauge, 2ft. 6in. track. But that made no allowance for the atrocious conditions under which the men had to work, hacking their way through dense forest, clearing tall trees simply to get a line of sight. There were no maps, and no way of getting an overall view of the territory. An engineer had to rely as much as anything on experience and instinct, and even then he could never be sure that there was not a better line to be had perhaps no more than a few hundred yards away, out of sight in the deep forest.
Ferrying the first locomotive to reach British Central Africa across the Oyan River in 1900
The same conditions were true on other routes inaugurated by Shelford. The Gold Coast had an excellent case for railway construction. The name was not fanciful: gold was found, not, unfortunately for the miners, on the coast, but some forty miles inland and protected by thick jungle. The railway surveyors selected what was at the time a huddle of huts along the shore at a village called Sekondi as the harbour and terminus of the railway. The actual survey was extraordinarily difficult. The land was full of humps and hollows under a thick cover of vegetation that evened them all out as far as the eye could detect. As a result, a surveyor could walk along what appeared level ground only to plunge up to his thighs in filthy water while releasing a cloud of mosquitoes eager to welcome the arrival of a substantial meal. Unexpected difficulties arose. The teams followed the usual pattern of clearing an area through the trees for sight lines, and then marking out the route with wooden pegs. They had not allowed for the extraordinary fecundity of the jungle. The pegs cut from green wood had scarcely been stuck in the ground before they began putting out fresh shoots, and by the time the surveyors returned, their surveying pegs were indistinguishable from any other forest saplings. In spite of all these problems, a line was built, but only at a cost of great personal hardship. Between August 1898 and May 1901, no fewer than ten chief engineers were appointed, as one after the other fell sick and had to leave the region. Other railways along the coast were built; all presented great problems. In Nigeria, for example, where building out of Lagos began in 1893, the main obstacle was the river Niger, not bridged until 1916. But if any one line could be said to sum up the African experience, then it must be the Kenya and Uganda Railway. Such was its share of hardships, failure, triumphs and high drama that it was known – for reasons that became all too apparent to everyone concerned in its construction – as ‘The Lunatic Line’.
The ostensible object of the railway was that noble one of laying a line to the interior that would hit at the heart of the slave trade: the actual motive was to reach Lake Victoria and establish territorial rights before the Germans. The line was the responsibility of the Imperial British East African Company, but was paid for by the British Government. In August 1891, Major J.R.L. Macdonald was appointed chief engineer. He had just returned from India where he had been engineer on one railway and had surveyed two more. An expedition had already been sent out under Captain Lugard to raise the flag in 1890, and now he was to be followed by Macdonald’s survey party. Local opinion had it that in order to travel into the interior, he would need a company of native infantry and a Maxim gun. Instead he opted for a party of forty, made up of Pathans and Punjabis, who as well as being experienced chainmen and staff-holders were ferocious fighters. However, as he was being asked to conduct a survey over 500 miles of difficult country in just nine months he did request some help. Three Royal Engineer officers were added to the party to help with the work, and Captain Pringle was made second-in-command. The balance between military
and civilian duties was neatly encapsulated in his own account, Soldiering and Surveying in British East Africa.
The route was to begin on the Kenya coast at Mombasa and Macdonald, viewing it for the first time, found it ‘far from cheering from the standpoint of a railway survey, though wonderfully beautiful from an artistic standpoint.’ He was also introduced to the pack animals bought for the expedition – 120 donkeys – but by the time Macdonald saw them half had already died ‘and others were evidently desirous of following the bad example thus set.’ Macdonald then set off with Pringle to try their hand at a little triangulation on a plateau fifteen miles from the coast. It was not an encouraging experience.
The discomforts of this preliminary canter were considerable; it rained on the average twice a day, and on one occasion my camp went astray. We laboriously cut our way through dense jungle to the summit of a commanding hill, only to find that the view did not extend to a greater distance than fifty yards. We realised the pleasures of chaining a base in long wet grass, full of holes and pools of water in which the chainmen not infrequently took an involuntary bath, a proceeding not conducive to accuracy in measurement. To add to my discomfort, my interpreter was a fraud as regards his knowledge of English, and supplemented it by a barbarous lingo which he called Hindustani, but which had little resemblance to the Hindustani spoken in India. When we got back to Mombasa after five days of this sort of thing, we both agreed that survey work in the interior could not be classed as altogether amusing!
Macdonald seems to have been a man blessed with a laconic sense of humour, and he needed it. The time had come to start the survey proper: Pringle was to take one contingent and follow the well established caravan route; Macdonald adopted the more difficult task of hunting for a wholly new line along the valley of the Sabalei River. The day of departure arrived.
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