Complex sentence: Macrae and Clarke soon agreed to cooperate on the design of a new weapon, but they quickly abandoned any thought of a towed mine as impractical; instead they worked on a bomb that could be carried by a diver and attached directly to a ship.
Split into simpler sentences: Macrae and Clarke soon agreed to cooperate on the design of a new weapon, but they quickly abandoned any thought of a towed mine as impractical. Instead they worked on a bomb that could be carried by a diver and attached directly to a ship.