TOWCON

TOWCON 2000 is a control system for controlling and monitoring all towing functions, shooting the tow wire, towing the towed object and hauling the tow wire.

The system handles both dynamic towing, hydraulic braking and static towing with brakes.

All data as wire lengths, adjusted max tension, actual wire tension, wire speed, motor pressure, motor temperatures and motor R.P.M. is presented on a high resolution LCD graphical monitor.

The system alarms the user in case of unexpected occurrence, or to warn about special conditions.

Alarm limits; wire data and control parameters can easily be programmed. Several functions can be simulated, and there is a system for error detection. Statistical data can also be read.

The system has small mechanical dimensions, and is easy to mount.

Instruction for use of Wire Drums

Following text and sketches are from the instruction books for the hydraulic winches delivered to the “B – type”. Sales & Service, I.P.Huse, Ulstein Brattvaag, Norway issues the instructions.

Please note the last four lines in section 4.2

Changing of Chain Wheels (Wildcats / Chain Lifter)

It will occasionally be necessary to change out the chain wheels depending on the size of chain to be used. As the size of chain wheels has to fit to the size of chain.

Chain wheels are manufactured for chain of a certain size and using it for other sizes can cause damage to both the chain and the wheels.

It is important that the chain fits exactly in the pockets to prevent the chain from slipping. A chain, which is not fitting in size, can wear the chain wheel down in a short time and is timeconsuming to weld and repair.

It can be a troublesome task to change out a chain wheel if it is stuck on the shaft. Which is often the case when working for a long time with tension of 150 tons or more. Also if some of the links in the chain did not fit exactly in the pockets and have been slipping which gives large loads on the chain wheel.

Large hydraulic jacks and heating is not always sufficient to dismantle a chain wheel. In most cases time can be saved by fitting an "I" or "H" girder to support in one of the kelps of the chain wheels and welded to a Doppler plate on deck to distribute the weight. The winch is then rotated in “local control” counter wise to create a load on the chain wheel. This should cause the chain wheel to come loose allowing the wheel to be dismantled.

Changing of chain wheel can take anything from 8 hours to 24 hours depending on where and who changes the chain wheel and is often subject to discussion between charter and company as time used is often for charters account.

It is still the responsibility of the ship to ensure that safety rules and procedures are adhered to even when shore labour is assisting. Emphasising the need to observe that pulling devices are used in a correct manner to avoid damage to threads. Likewise it is important to supervise the use of hydraulic tools to prevent damage to winch motors and anything else which might be used as a “foundation” for the hydraulic tool.

When the chain wheel has been changed often the changed out wheel is stored at shore.

Before sending ashore it is imperative to preserve it in a satisfactorily way. Lots of chain wheels have been stored out doors without proper protection and supervision. These chain wheels have to be scrapped. It is the responsibility of the ship to ensure the proper preservation and storing.

NOTE.

A return advice must always be filled out for chain wheels being landed.