As at Stirling and Carlisle, the Highlanders were not suited to lengthy siege operations, while "Baltimore" continued to land raiding parties up and down the loch. Frustration at being unable to protect their lands led to disputes between the Camerons and MacDonalds, and also with the French troops who did most of the construction work. On 27 March, a new battery of four 6-pounder guns above the Governor's garden opened fire but the strength of the exterior walls meant the focus shifted to making the interior untenable. On 28th, artillery on the eastern side opened up using heated shot, together with grapeshot, old nails and red-hot lengths of notched iron intended to lodge in the timbers.