Buller proclaimed his intention of attacking Botha by a preliminary bombardment of the Colenso kopjes on December 13 and 14; but the burghers lay low and gave so little indication of their presence that it almost seemed that they had abandoned the line of the Tugela. The British Army was encamped near Chieveley four miles south of Colenso.
On the evening of December 14 the scheme of attack was delivered to the Brigadiers. The leading idea of it was a frontal attack to be delivered from the village of Colenso, where the Tugela is crossed by an iron railway bridge as well as by an iron wagon bridge. The latter had been left intact by the enemy, possibly in order to entice the British troops across the river. Buller appears to have been unaware how far the Boer trenches extended towards the west, and to have assumed that only the kopjes immediately opposite Colenso were occupied. Hildyard's Brigade was ordered to march in the direction of the "iron bridge,"[21] to cross at that point, and then to "seize the kopjes north of the iron bridge." The attack on the enemy's right, which was believed to be weak, was assigned to Hart's Irish Brigade. He was instructed to cross the Tugela at a bridle drift about two miles west of Colenso and work down the left bank towards the occupied kopjes. Two infantry Brigades were retained as reserves to be used when required; and the mounted Brigade was ordered to move towards Hlangwhane and occupy it, if possible, and cover the right flank; but the weakness of the Boer position on that hill, which was cut off by the river from the main line of defence, does not seem to have been realized. A few batteries were sent with Hart, but the bulk of the artillery was ordered east of the railway to support Hildyard.
Buller's scheme has been severely criticized ever since its failure, but Clery who was in nominal command of the Natal force, and in whose name the battle orders were issued, as well as the other general officers, acquiesced in it. But in fact hardly any scheme could have been devised more likely to play into Botha's hands. Buller hoped to get a footing on the left bank and Botha hoped that he would succeed in doing so. Botha's special idea was to allure the troops of the frontal attack to his own side, where he could easily pound them from his kopjes and carry out his general idea of netting the British flanks.
Buller had not then been in action with the Boers and he probably underrated their tactical capacity; but already he seems to have contemplated the possibility of the loss of Ladysmith, for in his despatch of December 13 to Lord Lansdowne, in which he justified his sudden change of the plan of campaign, he said that "it would be better to lose Ladysmith than to leave Natal open to the enemy."
Nor did the Boers enter into the contest with much confidence. They had not yet tried Buller's mettle and his name was to them a tradition of courage handed down from the Zulu war, in which some of the older burghers now opposing him on the Tugela had served under him. The curious omission to inform White in Ladysmith that an attack on Colenso was to be made on December 15 may have arisen from Buller's doubts as to its issue, or from reluctance to heliograph a message in a cipher of which the enemy might have the key.
The story of the Battle of Colenso is mainly the narrative of the action of two important components of the Army of Natal. Each of these was led by a dangerously brave man, whose impetuosity crippled the tactical scheme and whose method of working his command was, at least, unusual. If in Hart and Long, who commanded the Artillery, the quality of personal courage had been less prominent it is probable that Colenso would not have filled up the cup of Stormberg and Magersfontein in that dark midsummer December week.
The naval guns on the west of the railway had the honour of opening the battle, and shelled Fort Wyllie for some time without eliciting any response. Long joined Hildyard with another naval battery and two field batteries. He was not only an impetuous man but he also belonged to the short range school of artillerists;[22] and he soon outpaced his infantry escort and came into action with his field batteries in the open a little in advance of a shallow intersecting donga, and within 1,100 yards of the Boer entrenchments across the river. The naval battery had been compelled by the flight of the Kaffir ox drivers to outspan astride a deeper donga about a quarter of a mile in rear, to which Long had sent back his gun teams. A terrific rifle and shrapnel fire, which the infantry escort which soon came up was powerless to subdue, was now opened upon the guns, and for an hour the batteries were beaten on until the casualties left but four men to each gun, and ammunition was running short. Long, who was one of the first to be wounded, withdrew the dwindled gun detachments to the shallow donga and sent back for a fresh supply of ammunition, intending to resume fire as soon as the general attack developed.
All the while the batteries had been unsupported except by the escorting companies, which were not under Long's orders, and no attempt was made by Hildyard's or Barton's brigade in rear to relieve or divert the pressure on the guns, which had succeeded in silencing temporarily some of the Boer artillery and in checking the rifle fire.
Earlier in the action Buller had been informed that the guns were "all right and comfortable," but later reports gave him the impression that this cheery optimism was delusive, and that owing to loss of men and exhaustion of ammunition the artillery told off to support Hildyard was now permanently out of action. The rest of the artillery was engaged in assisting Hart, who was in trouble, and Buller came to the conclusion that the attack on the Colenso kopjes must be withdrawn.
Hart's Brigade was ordered to march "towards the Bridle Drift at the junction of the Doornkop Spruit and the Tugela, and to cross at that point." Here was yet another ambiguity. As there were two "Iron Bridges" so also were there two "Bridle Drifts," one on each side of the isthmus of the river loop, and yet another at the head of it. The West Drift was unfordable on the morning of December 15, and a hasty sketch which had probably been filled in from hearsay evidence and which was Hart's only map, showed the Doornkop Spruit as entering the Tugela below that Drift instead of just above the East Drift.[23] The sketch also duplicated the loop.