Siege of Khartoum support of the Mahdi, and cut the Egyptian traffic on the Nile and the telegraph to Cairo. Communications were not entirely cut, as runners could still get through, but the siege had begun and Khartoum could only rely on its own food stores, which could last five or six months. On 16 March an abortive sortie from Khartoum was launched, which led to the death of 200 Egyptian troops as the combined forces besieging Khartoum grew to over 30,000 men. Through the months of April, May, June, and July, Gordon and the garrison dealt with being cut off as food
HMS Khartoum (F45) and the sloop in search for "Torricelli" near Perim Island. After interception, "Khartoum" and these warships took part in a surface engagement with the submarine, during which "Torricelli" was sunk and "Shoreham" damaged. However, during the battle, "Khartoum" was hit by return fire which damaged the after torpedo tube mounting. Some five and a half hours later, at 11.50am (local time), a torpedo's compressed air chamber exploded, propelling the warhead through the deck house of number 3 4.7-inch mount. and causing a serious uncontrollable fire from a ruptured oil tank there. This resulted in an explosion of the ship's artillery