Technology from Europe:
The Netherlands

Special winch for handling personnel

Winching people onboard offshore platforms can still be, and regularly is, a cause of dangerous conditions despite observance of all applicable safety measures. To curb these risks, safety standards are constantly revised and upgraded. One of the current topics of discussion is the service winch with which both goods and persons are hoisted. In recent years, the discussion has prompted a rise in demand for winches exclusively designed for lifting people. With this objective in mind, the Dutch Machinefabriek EMCE (EMCE) in Voorhout, a subsidiary of Stokvis Holding, announces its new manriding winch. 

Offshore platforms all over the world make use of combined service winches for a variety of purposes. One may think of hoisting personnel into the tower to carry out various projects and of hoisting people onboard offshore platforms, but the winches are also utilized for the hoisting of supplies, heavy parts and equipment. Usually, various combined-service winches are available on an offshore platform. 

Although the people onboard an offshore platform cannot operate without combined winches, their use is not without risks. Thus, when people are winched up in a safety harness or a cage, unsafe situations may arise as the winch is operated with excessive force – at times, the results can, and have been, fatal. The combined-service winch, as such, cannot be blamed for this, because design is nothing more than one of delivering brute force. It is a challenge, thus, to design a winch by means of which these risks can be limited. Hence, EMCE came up with the idea of developing a manriding winch. 

The result is a winch exclusively dedicated to hoisting one person at a time in a so-called safety harness or boatswain seat, with a maximum weight of 150 kg, at a variable speed of 0 – 28 m/min. Bearing in mind the applicable international standards in this field, the developer opted for a manriding winch with a grooved drum and a drum diameter of 238 mm, and a cable diameter of 10 mm – therefore, a drum factor of 23.8. 

As standard, the winch is delivered with a helical shaft-mounted gearbox, which is driven by a pneumatic vane motor with an operating pressure of 6 bar and a speed of 2,500 rpm. If required, the motor may be replaced by a hydraulic or flameproof electrical motor. 

Manriding winch for safely lifting/ lowering people on an offshore platform.

In developing the winch, EMCE opted to equip the drive system with a pneumatic motor, and make it suitable for application in Zones 0, 1 and 2. The use of compressed air has the added advantage that there is no danger of sparks. And the system comes equipped with a mechanical/pneumatic overload safety, a slack cable detector and a drum guard. The current requirements of HSE, DNV, NPD, Lloyds and ABS formed the basis for the development. Further, a special biased control valve helps prevent excessive acceleration of descending loads. 

The manriding winch now being put on the market is, as standard, prepared to be connected to a nitrogen accumulator. Especially in emergency situations, this may be a great help in making it possible to lower the winch at all times. And the company has broadened its existing range of manriding winches of up to 5 mt with this most recent introduction.