On 4th March the South Africans were relieved by the 26th Brigade, and marched from Arras to the neighbourhood of Ostreville, where they began their intensive training for the coming offensive. Their casualties during the previous three months in the line had been 2 officers and 49 other ranks killed, and 5 officers and 166 other ranks wounded. The health of the men, considering the severity of the weather, had been extraordinarily good, and only twenty-eight cases of trench feet were reported. As was dryly observed, the doubt as to whether they could stand a northern winter was settled by keeping them continuously in the trenches. On 5th March Sir Douglas Haig inspected the 1st and 4th Regiments, and complimented them highly on their smartness; and on 11th March the 1st, 2nd, and 4th Regiments were inspected by the Colonial Secretary, Mr. Walter Long. While the South Africans were beginning their intensive training, the Germans were completing their retirement from the Bapaume Ridge to the Siegfried Line. At the hamlet of Tilloy-lès-Mofflaines, on the Arras-Cambrai road, this line branched off from the old front. Beaurains was now ours, and Arras was therefore free from its former encirclement in the south. The German position from the northern pivot of the new Siegfried Line to Lens was very strong, consisting of three main systems, each constructed on the familiar pattern of four parallel lines of trenches studded with redoubts, and linked up by numerous switches. A special and very powerful switch line ran for 5½ miles from the village of Feuchy northward across the Scarpe to beyond Thélus, and constituted what was virtually a fourth line of defence. The whole defensive belt was from two to five miles deep, but the German High Command were not content with it. They had designed an independent line running from Drocourt, south-east of Lens, to the Siegfried Line at Quéant as an alternative in case of an assault on the Arras salient. Towards the close of March this position, which was to become famous as the Drocourt-Quéant Switch, was not complete. It was intended as a protection to Douai and Cambrai, the loss of which would have made the whole Siegfried system untenable. But it was designed only as an extra precaution, for there was every confidence in the mighty ramified defences between Lens and Tilloy and in the resisting power of the northern Siegfried section. The country through which the German positions ran was peculiarly suited to their purpose. It represented the breakdown of the Picardy wolds into the flats of the Scheldt, the last foothills of the uplands of northern France. Long, low spurs reach out to the eastward separating the valleys of the Scarpe, the Cojeul, and the Sensée, and their sides are scored with smaller valleys—an ideal terrain for a defensive battle.