How many do you know about commonly used tugs at sea
The main types of tugs commonly used in offshore construction operations include: AHT, AHTS, ocean rescue tugs, etc. The following is a general introduction to each type of tugboat.
1. AHT（Anchor Handling Tug）
Ship data: length 45.7m, beam 13m, depth 6.3m, draft 4.7m, power 9900 HP, bollard drag 120T, tow cable 1200mx64mm, side thrust 2x600HP.
Tug characteristics:
- It has good seaworthiness, maneuverability and working performance in bad weather.
- Equipped with two rollers, it can work continuously for a long time.
- Relatively low freeboard, easy to grab the buoy and anchor.
- The side of the ship is equipped with larger fenders, which can be used for side towing operations when there are storms and waves on the sea.
- No additional equipment is required to switch from towing operations to anchoring operations.
- The design of the stern allows the anchor chain and short rope to pass under the stern without touching the rudder, paddle and other equipment.
- The bow is equipped with a fender and can be used for pushing operations.
Tug suitability:
- It can perform anchoring operations on barges and platforms, and is especially suitable for high-speed anchoring operations on barges.
- Good maneuverability and high-power design are suitable for anchoring operations in restricted waters in bad weather.
- It is especially suitable for towing and loading and unloading operations for pipe-laying ships and platform construction barges at sea, because this type of tugboat can get as close as possible to the barges.
- Suitable for anchoring operations in strong winds, strong currents, and water depths below 250 meters.
2. AHTS (Anchor Handling Tug Supply vessel)
The length is 74m, the width is 16.4m, the molded depth is 8.0m, the draft is 5.7m, the deck loading capacity is 1300T, the power is 13300 HP, the bollard drag force is 150T, the tow cable is 1400m×72mm, and the side thrust is 3×1000HP.
Tug characteristics:
- The ship size, main deck area, main engine power, and bollard drag force are relatively large.
- Equipped with multiple side thrusts and azimuth propellers, it has good maneuverability and can adapt to bad weather operations.
- Equipped with high-power and large-sized main towing machine and working towing machine, as well as a powered backup drum, suitable for deep water operations.
- There is a large anchor chain cabin (for storing anchor chains other than the own ship).
- It has a large area ofstern deck, and can store anchors, buoys and other equipment on the deck during continuous towing and anchoring operations of the tugboat, and can perform related operations.
- Can store large amounts of fresh water and fuel.
- The deck is designed to meet many special purposes, such as installing spare power rollers, cranes, “A” frames, and ROV operations.
Tug suitability:
- It can meet most requirements of oil field operations, wind power operations and offshore operations: towing, anchoring, and transporting groceries on the main deck. The deck below the main deck is equipped with various cabins and tanks, which can carry various solid bulk cargoes and Liquid cargo.
- The large-area deck and large-area anchor chain cabin can carry out anchoring operations at a single point (single buoy mooring SBM).
- A high-power cable car can be used to anchor the platform in deep water.
- Good towing performance, endurance and its bollard drag force of more than 130 tons can increase the adaptability of ocean towing.
- It can be applied to the towing and anchoring operations of some special offshore facilities, such as the towing and positioning of large gravity base platforms, tension leg platforms (TLP) and other similar offshore facilities.
- Suitable for maritime rescue in multi-tasking situations.
- Suitable for anchoring operations of pipe laying ships and platform construction barges.
3. Ocean Going Tug
Ship data: length 68m, beam 13.5m, depth 7.8m, draft 6.9m, power 10000 HP, bollard drag 120T, tow cable 1700m×66mm, side thrust 1×1000HP.
Tug characteristics:
- The larger power, bollard drag force, displacement and hull shape are all designed to adapt to the worst weather operations.
- A single ship has fast sailing speed and good maneuverability.
- The towing machine is specially designed to store a very long towing cable, so it can absorb the very large tension generated during towing.
- Usually equipped with multiple auxiliary drums, winches, cranes, work boats, fire-fighting facilities, anti-fouling equipment, etc.
- Equipped with a large number of rescue and towing facilities: heavy-duty diving equipment, rescue anchors and pulleys, portable water pumps, generators, and commonly used tools in workshops.
- The tail deck is relatively limited and is mainly used for towing operations and cannot be used for anchoring operations.
- Large amounts of fuel and spare parts are stored to ensure long battery life.
Tug suitability:
- All types of rescue tugs can be used for fire rescue, damage control, rescue towing, etc.
- Rescue stranded ships, sunken ships, aircraft and other targets.
- It can carry out ocean towing for all types of floating facilities.
- For highly professional maritime operations, both the country and the military require tugs with long endurance and good seaworthiness.