 Converting Campbeltown for the raid took ten days . She had to be lightened to raise her draught to get over the sand banks in the estuary . This was achieved by completely stripping all her internal compartments . The dockyard removed her three 4 inch ( 100 mm ) guns , torpedoes and depth charges from the deck and replaced the forward gun with a light quick – firing 12 pounder ( 3 " ) . Eight 20 mm Oerlikons were installed on mountings raised above deck level . The bridge and wheelhouse were given extra armour @-@ plate protection , and two rows of armour were fixed along the sides of the ship to protect the Commandos on the open deck . 
 Converting Campbeltown for the raid took ten days . She had to be lightened to raise her draught to get over the sand banks in the estuary . This was achieved by completely stripping all her internal compartments . The dockyard removed her three 4 inch ( 100 mm ) guns , torpedoes and depth charges from the deck and replaced the forward gun with a light quick – firing 12 pounder ( 3 " ) . Eight 20 mm Oerlikons <a href='uninflect' title='1'><mark>were</mark></a> installed on mountings raised above deck level . The bridge and wheelhouse <a href='uninflect' title='2'><mark>were</mark></a> given extra armour @-@ plate protection , and two rows of armour <a href='uninflect' title='3'><mark>were</mark></a> fixed along the sides of the ship to protect the Commandos on the open deck . 
Converting Campbeltown for the raid took ten dayz . She had to be lightened to raise her draught to get ova the sand banks in the estuary . dis was achieved by completely stripping all her internal compartments . The dockyard removed her three 4 inch ( 100 mm ) guns , torpedoes and depth charges from da deck and replaced the forward gun wid a light quick – firing 12 pounder ( 3 " ) . Eight 20 mm Oerlikons was installed on mountings raised above deck level . The bridge and wheelhouse was given extra armour @-@ plate protection , and 2 rows of armour was fixed along the sides of the ship to protect tdaCommandos on thdapen deck .