 However, "Albacore", "Arab", "Bonetta", "Cobra" and "Express" were builder's specials, and had steam turbines fitted in addition to, or in lieu of, the reciprocating engines, giving to for .Armament was one QF 12-pounder gun on a raised platform at the rear of the forecastle, five QF 6-pounder guns (two sided abreast the conning tower, two sided between the funnels and one on the quarterdeck) and 2 single torpedo tubes for 18-inch (450 mm) torpedoes.The last two Palmers boats, built in 1908, were replacements for the "Gala" and the C-class "Tiger" that had collided and sunk that year.