Tugs working a ship in

Added or changed on 13 October 2026

• A ship towed in by tugs is brought to its berth (chosen as any ship's is) by a series of real tug manoeuvres, worked out for its own pier. Every tug only ever goes the way it faces (ahead, or straight astern), turns on the spot (harbour tugs can) or steers round, or lies with its fender on the hull pushing; the ship only turns about a point or goes straight along its length: nothing slips sideways, and nothing backs through a pier. 1. Towed in: the lead tug pulls on its line ahead; the other lets go inside the breakwater, waits beside the way in while the ship passes, then makes fast astern on a line of its own (drawn from its bow to the ship's stern) to steady it. The ship stops in the channel abreast of its slot; the lead eases out to the side away from the slot and stops beside or ahead of the bow, short of the basin's end. 2. Stations: each lets go and goes round to push: out to the side, along, turned square to the hull and in until its fender's on it; the lead on the bow from the side away from the slot, the other on the stern from the slot's side. 3. Turned: pushing bow and stern opposite ways they turn it about a point near its middle until it faces straight into its slot (where it couldn't lie along the channel abreast of its slot, it's towed round a quarter circle on the hip instead). 4. Pushed in: with no room astern of it yet (a long ship in a narrow channel: a tug there would be in the slot across the way), the one pushing makes fast alongside its stern quarter on the hip before it's turned (approached from astern along the channel, where there's room) and pushes it part way in made fast there; then it lets go, comes round astern, its bow on the stern, and pushes it the rest of the way in a few pushes, easing off between. The lead backs off and stands by. 5. Clear: the pusher backs straight out of the slot to just past the channel's middle and steers round for the way out; then both go to their moorings.
• Which point it turns about, where the tugs push, which side the hip tug lies, whether it's turned about a point or round a curve, and whether the tugs turn on the spot or steer round are chosen for each pier, ship size and team from a list of ways, the first that keeps the ship and tugs clear of the piers, the basin's walls, the breakwater and the ships at every other berth (each taken to hold the biggest ship it can) at every moment, with no jumps, snaps or sideways slips. All 3,592 cases (every berth of the four marina sizes, every ship size and small ships sharing a big berth towards either end, one tug and two, either side of the entrance) were checked at 400 moments each and all are clear. The berthing takes the whole of the work (about 40 to 60 s of play). Tugs in port draw no wake of their own.
• Marinas got turning water for it: the last slot each side has its own pier on its land side (no berth lies against the basin's end wall any more), and the basin runs on past it by 0.6 of the longest ship's length of open water, the quay, HQ, industry and town behind it moving back with it.