Emergency Towing Arrangement

The IMO’s guidelines MSC 35 (63), adopted on 20th May 1994, require an emergency towing arrangement to be fitted to the forward and aft end of the tanker. The aft arrangement must be possible to rig in 15 minutes under harbor conditions, while the forward one has a permitted deployment time of 60 minutes. The arrangements need to be kept simple, as the equipment may have to be employed in bad weather and in complete darkness if the vessel is powerless.
The emergency towing arrangement at the aft end of the vessel must consist of pick-up gear, a towing pennant, chafing gear, a fair lead, a strong point and a roller pedestal. There are strength requirements for most parts. Furthermore, it is a particular requirement for the aft arrangement that the pick-up gear can be released manually by one man only. At the forward end, the pick-up gear and the towing pennant are made optional, but there is to be a strong point, a fair lead and a chafing chain.
The towing components need to have a working strength of at least 1,000 kN2 for tankers between 20,000 and 50,000 tonnes dead weight, and of at least 2,000 kN for vessels of greater tonnage. Working strength is defined as one half ultimate strength. The strength should be sufficient for all relevant angles of the towline, including a 90° pull to either side, and a 30° vertical pull downwards. Such requirements make it necessary not only to strengthen the vessel’s hull at the strong point for the towing attachment, but also at the fair lead point. The towing pennant is required to have a length of at least twice the lightest seagoing ballast free board at the fair lead, plus 50 meters. The requirements for the chafing gear allow for different designs, but if a chain is used, it should be fixed to the strong point and reach at least three meters beyond the fair lead.
Before abandoning vessel, the crew is expected to drop the pick-up gear overboard at the stern of the vessel. Some manufacturers use only one buoy on the pick-up rope, others use two, claiming that it is much easier to get hold of a rope between two buoys, than the buoy itself. The buoys should be fitted with a light to facilitate detection at night. While the forward gear is installed in the vessel’s center line, the aft gear is often installed off center, where space is available. The gear is therefore not meant for long tows, only emergency use. Some owners have preferred to install the gear under deck, where it is better protected.

1 International Association of Classification Societies.
2 kN = kilo Newtons.

Today emergency towing arrangements are in place on tankers above 20,000 tonnes dead weight, and it is believed that the equipment will prove its worth in years to come. Opinions have also been voiced in favor of fitting such gear to other large vessels, like bulk carriers and cruise vessels. The installations are relatively inexpensive to fit on new vessels, and represent an added safety and loss preventive factor for all large vessels.

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[SatishYadav-kstl]

Good animation here untill 2:31 when the towing pennant is shackled to the chaffing chain, its dangerous to let the tug pull the chain without the chain being controlled, it will get paid out uncontrollably and end up falling by gravity on the tug boat or in the water . Correct procedure would be to connect the other end of the chaffing chain to a messenger line the 40 mm STS messenger we use for STS ops and pass it to the tug boat and then slowly taking the weight of the chain -messenger rope on the winch of the tug boat.Then release the stopper on the ship and continue heaving on the chaffing chain through the bow chain stopper and then put the stopper brake as necessary. Then remove the STS messenger connected to the shipboard end of the chaffing chain.Vessel is ready to be towed.

[ernomore]

When empty a tanker ship looks so huge, good illustration though, thx

[DB-thats-me]

In the slide showing what had ‘failed’, that is taken away. I would liked to have seen what needed to be added. NOC day shapes. Vis, two black balls, hung vertically, at ships wast, where best seen.
Picky I know, but still in the Regs.

[naturalezaysereshumanos]

Thanks so much for the information! 🙏🤝👏

[ammaralhawsawi]

Good illustration. But can’t the tug line be secured directly to the ship’s bit?