Nearly all sailing masts are guyed. The sails are trimmed by rotating the masts. The wires are supported by small masts or towers or rock anchors. In addition, there were ten sailors handling the masts and the sails. The steamer also was provided with functioning sails for her masts and yards. Shukhov was responsible for constructions of a new types of lighthouses, masts, and transmission towers. Early bomb vessels were rigged as ketches with two masts. Both ships were fitted with lattice masts. The and s use photonics masts rather than hull-penetrating optical periscopes. A brig is a sailing vessel with two square-rigged masts. It has three DynaRig masts supporting a sail area of . This is a list of catastrophic collapses of masts and towers. She was also provided with secondary masts for sail power. The masts and funnels were also fitted before launch. This becomes difficult on larger boats with heavier, longer masts.