As might be supposed from the low cost of the line (£4,500 or $22,500, per mile), the engineering work was not of an elaborate character. Rapidity of construction, combined with low cost, were the two governing considerations that had to be borne in mind, for the sooner railway transportation was provided, the earlier settlement would take place. The terms governing construction demanded that the line should be of such a character as “would be capable of effectually conveying traffic at a speed of twelve miles an hour on completion, and that grades and curves were not to be sharper and heavier than generally prevailed upon a line of this gauge.” Ballasting was only to be used on such portions of the line as was necessary to ensure the safe running of the trains during the rainy season. In laying the road very little regard was paid to formation, and wherever the surface of the ground was even it was followed, the steel sleepers being packed with the minimum of ballast to give a moderately smooth running top. The shallower streams and rivers were not bridged, but the railway was carried across over a ford. If the water rose above the track a few inches, a thrilling spectacle was offered when a train crossed. It would creep carefully down the bank and crash full tilt into the water, sending up a column of spray which entirely obliterated the front of the engine from view. Later, the line was overhauled and brought into conformity with modern requirements, bridges of steel being introduced to span all obstructions of this character. Timber was impossible, owing to the ravages of white ants, though creosoted wood was found to offer a substitute for the metal for a short period, and was adopted sparingly. Buluwayo lies at an altitude of 4,400 feet, and from this point the line falls steadily until it gains the Gwaai River, 1,200 feet lower. Crossing this waterway, the line makes a straight cut across the flat, sandy and wooded country for 71 miles as the crow flies, to enter the Wankie coalfield. In this district the surface run could not be continued, and consequently heavy cuttings and embankments had to be carried out over a distance of 59 miles. Beyond the Wankie coal territory, and 282 miles north of Buluwayo, the line ran up against the first serious physical difficulty, but one of such proportions as to make amends on the part of Nature for the easiness of the grading hitherto. This was the Victoria Falls on the Zambesi River, and the location of the line compelled a crossing of this magnificent waterway just below the cataract, where the water, after tumbling over the ledge, is forced through a deep, narrow gorge 400 feet in depth.