LASHING UP A TUG
When a ship is moved as a dead ship it is often effective to lash a tug up at her bow or stern. The tug lies alongside and puts up a head line, stern line, and an aft leading spring line to the ship. The head and stern lines are kept as short as possible, leading as much like breast lines, and heaved up very tight. It is important that these lines be tight so the ship and tug work as a unit, or the lash-up will be more of a hindrance than a help. Do not allow the ship to be moved if it is not possible to get a tight lash-up due to the ship's draft, hull configuration, or the location of her chocks and bitts.
The tug or tugs may be lashed up on the stern and used in place of the ship's engine and/or rudder. If a tug is lashed on each quarter, the ship is handled much like a twin-screw vessel. In sheltered waters a large ship can be moved significant distances quickly and safely in this manner. When using tugs in this manner helm and engine orders similar to those used aboard a twin-screw ship are appropriate.
When only one tug is lashed up, the off center location of the tug is felt until the ship has some headway, so the ship initially tends to move laterally away from the tug. It is more effective to back the tug to turn the ship to the side on which the tug is lashed up, back a tug lashed to the port quarter to turn the ship to the left (stern to right, bow and ship to the left). Once it has headway a small ship can be moved with only one tug lashed up.
The other common type of lash-up places the tug on the ship's bow heading aft. This might be done when only one tug is used to back a ship from a berth around another ship docked astern or to back a dead ship from a berth. After being lashed up the tug is backed to move the ship's stern off the dock to get clear of the berth and around any ship astern. When the ship has sufficient angle to the berth, the tug comes ahead as needed to steer the ship from the berth. Helm orders are used that are similar to those used to move the ship from a berth under her own power.
When leaving the berth stern first, left rudder is used by the tug to move the ship's bow to port and her stern to starboard. This can be confusing, so face aft in the direction in which the ship is moving, and give helm orders to the tug. The maneuver is immediately simplified and the helm orders needed are obvious. Once clear of the berth, with sternway on the ship, the tug is given a course or steadied on a heading and the tug master steers the vessel much as a helmsman would.
A ship with a tug lashed up can be stopped by backing the tug. If the tug is lashed up on the starboard quarter when moving ahead, or lashed up on the port bow when moving stern first, the ship will twist and can be handled like a single-screw ship with a right-handed propeller.
A lashed-up tug can often do the work of two tugs when used together with the ship's engine moving a ship laterally without developing headway. Use of a tug in this manner requires close cooperation between the shiphandler and tug master, as well as a good tight lash-up. The tug lashes up at the bow heading aft. She comes ahead with her rudder hard over in the direction of the pier while the ship uses her engine ahead and rudder hard over in the direction of the pier.
