A further question immediately arose:  Should the railway to Abu Hamed start from Korosko or from Wady Halfa?  There were arguments on both sides.  The adoption of the Korosko line would reduce the river stage from Assuan by forty-eight hours up stream.  The old caravan route, by which General Gordon had travelled to Khartoum on his last journey, had been from Korosko via Murat Wells to Abu Hamed.  On the other hand, many workshops and appliances for construction were already existing at Wady Halfa.  It was the northern terminus of the Dongola railway.  This was an enormous advantage.  Both routes were reconnoitred:  that from Wady Halfa was selected.  The decision having been taken, the enterprise was at once begun.

Lieutenant Girouard, to whom everything was entrusted, was told to make the necessary estimates.  Sitting in his hut at Wady Halfa, he drew up a comprehensive list.  Nothing was forgotten.  Every want was provided for; every difficulty was foreseen; every requisite was noted.  The questions to be decided were numerous and involved.  How much carrying capacity was required?  How much rolling stock?  How many engines?  What spare parts?  How much oil?  How many lathes?  How many cutters?  How many punching and shearing machines?  What arrangements of signals would be necessary?  How many lamps?  How many points?  How many trolleys?  What amount of coal should be ordered?  How much water would be wanted?  How should it be carried?  To what extent would its carriage affect the hauling power and influence all previous calculations?  How much railway plant was needed?  How many miles of rail?  How many thousand sleepers?  Where could they be procured at such short notice?  How many fishplates were necessary?  What tools would be required?  What appliances?  What machinery?  How much skilled labour was wanted?  How much of the class of labour available?  How were the workmen to be fed and watered?  How much food would they want?  How many trains a day must be run to feed them and their escort?  How many must be run to carry plant?  How did these requirements affect the estimate for rolling stock?  The answers to all these questions, and to many others with which I will not inflict the reader, were set forth by Lieutenant Girouard in a ponderous volume several inches thick; and such was the comprehensive accuracy of the estimate that the working parties were never delayed by the want even of a piece of brass wire.

In any circumstances the task would have been enormous.  It was, however, complicated by five important considerations:  It had to be executed with military precautions.  There was apparently no water along the line.  The feeding of 2,000 platelayers in a barren desert was a problem in itself.  The work had to be completed before the winter.  And, finally, the money voted was not to be outrun.  The Sirdar attended to the last condition.