92007 Seamanship, Towing Communication
More towing problems
- Night time. Variable light airs. Good visibility. Low Southerly swell.
- Report No. 92007.
This report is from the same tug, towing the same barge and occurred 28 hours later. By this time a second tug was assisting with the tow. Communication with the second tug had to be carried out through an interpreter with no technical knowledge. The Master of the reporting tug objected to this, he also objected to the proposed towing arrangement, he was over-ruled on both objections. We will refer to the reporting tug as tug A, and the second tug as tug B.
Tug A was towing from the centre bridle to two chaffing chains to Smit brackets. There was no Monkey face, but a 100 tonne "D" shackle to which was connected a 50mm x 50m fore-runner pennant, then a 16" x 50m nylon stretcher and 52mm x 350m tow line. As this was to be a relatively short tow in favourable weather conditions, with the water depth between 50 and 80 m, the length of tow was about right, with no scuffing of the bottom.
Tug B was towing from the port bow of the barge on a single line connected by a chaffing chain to a Smit bracket, then to a nylon shock/stretcher,then her tow wire. Her tow wire was run out to approximately the same length as ours. Power was brought up together to towing revolutions and alterations of course given degree by degree, allowance was made so that at all times she kept her station 50 to 60 m away on our port beam. A greater angle outward would cause her to 'get in irons', decreasing the Shortly before midnight, making 7.7 kts, tug B took a sudden and violent sdistance apart might make contact between the two vessels.
Throughout the day the steering of tug B was eratic as the wheelman lost his concentration. The OOW on tug A had to keep calling to remind B to keep station. heer to port and appeared to be increasing power, causing the angle between the two vessels to increase rapidly. The barge was now moving forward very rapidly and tug A ordered that both tugs reduce power. Tug A eventually managed to control the barge and brought it to a halt, allowing tug B to get back on station. During the period of attempting to check the barge tug A was in a dangerous GIRTING situation, not helped by being unable to communicate directly to the Master of the other tug.
As no proper communication could be made, it was assumed that either tug B had a main steering failure, or, as it was towards the end of the watch, the helmsan lost concentration. The interpreter said that at all times there was a man at the wheel. The reporting Master prefers to use automatic with constant monitoring.
Towing was resumed at a much slower speed of 4.8 kts and tug B was able to maintain station a little better.
The reporting Master makes the following comments:-
Towing such a barge with two tugs, it would have been preferable if the towing points had been from each bow of the barge, thus equalising the the pulling forces.
Alternatively, with the good weather, towing in tandem would have been a good option. There was however, no chain bridle available, apart from the bower anchors on either tug.
Perhaps better station would have been kept by tug B at a slower speed, but this would have defeated the purpose of having the extra tug. Tug A can tow at 5 to 6 kts solo, with all the problems encounterred with tug B, a safe speed was estimated to be 4 to 4.8 knots only.
I was astounded to find out after the incident that if I had needed to use the emergency quick release of the tow wire it would have been inoperable due to the dogs being in. This seemingly had been the practice aboard this vessel to avoid the inadvertant pulling of the lever and losing all the towing gear.