Wednesday, August 13, 2014

Cable Winch or Windlass

A cable winch is used to pull something with a cable, typically a steel cable. The cable spools around a drum, and the drum is turned to pull in the cable. During a tour of the LST 325 in Evansville, I came across enough examples of winches to provide pictures for a posting. The red thing near the lower-right corner below is a winch used to tighten the cable that helps hold the ship to the floating dock. In the closeup below that picture, you can see that the winch is hand-cranked and how the cable spools onto the drum.

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The winch below is power driven and holds a lot more cable. It is at the stern of the tank deck, and it is used to pull equipment onto the ship through the bow doors. It holds a lot more cable than the hand winch can hold!

At the rear of the ship on the weather deck is an even bigger winch. (I'll soon describe the two vertical cylinders.) That cable is at least an inch in diameter.

It is connected to an anchor that hangs at the back of the ship.

Note the triangular spade on the bottom of the anchor. When the LST makes landfall, it waits for high tide and then rams itself onto the beach sand. To get back off, they wait for another high tide, tow this anchor back out to see and then use the winch to pull the boat off the beach. When they were on a trip in Kentucky, they turned to avoid hitting a barge and plowed into a sandbar. Two Coast Guard tugboats could not get it off the sand bar. And then someone remembered that the ship was equipped with this anchor and winch. So they looked in the Yeoman's office and found the instruction book for the winch. It still worked, the Coast Guard towed the anchor away from the ship, and the winch was able to pull the ship off the sand bar. They have since greased the cable to help keep it operational.

Below is a view of the two vertical cylinders from the perspective of the cable.

Note the notches in the middle horizontal shaft. Those notches move the carriage holding the vertical rollers back and forth to guide the cable so that it smoothly winds onto the drum as the drum turns. The following picture is of the backside of the winch. The drum in the foreground would be a brake. At each end of the shaft in the middle would be gears that drive a chain that drives bigger gears on the ends of the drum shaft. What the little hand wheels control is probably why they felt a need to find the instructions.

From behind the winch, I took a picture towards the stern so that you can see the cable going from the winch  through a cable guide on the stern. The cable then goes down and holds the anchor we saw above.

Ben Stalvey posted two photos with the comment: "It's Manitowocs Mega Drum for the massive 31000."


A spiral grove is evidently machined into the drum to guide the cable. Jason Baker posted three photos with the comment:
I use to get all kinds of very difficult or jobs other people use to turn away on my 1960 King VTL. Here's an example of one of those jobs. These were 66" diameter x 60" tall cable drums with an .875 lead. Now, keep in mind my 1960 King VTL didn't have a half nur not was it designed to thread. The max feed rate of the machine was 1.00 I.P.R. In the 3rd photo you will see an external gear reduction I built to slow down the end out put of the transmission, with machine set at 1.00 lead the external gear reduction would decrease by 12.5% to obtain an .875 lead. This was very tricky, because I had to time the table, tool and starting and end points all exactly to get repetition on the rack and pinion.

I think this is the winch for the hoist for a shaft in an underground mine.
Max Cranes posted
MAX Heavy Lift Team provided specialised lifting services to a valued mining client, to unload and rotate a 140.5t Clarke Shaft Winder. Our 500t Terex AC-500-2 and 250t Liebherr LTM1250-6.1 cranes were used to complete the lift. View case study: #cranehire #cranes #craneservice #mining #miningequipment #heavylifting #heavyliftteam #remoteworking #terex #liebherr #southaustralia #usg #upperspencergulf
Geoffrey Fischer shared


  1. It is great to see such a piece of helpful information and thanks for sharing it.
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  2. very informative blog..keep update with your blogs..
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  3. From a retired Navy CPO [now gone]; the anchor was dropped on the way into shore. With the cargo gone, the hip drew less water and used the anchor to back off. They didn't hang around for the next tide, there was nasty people onshore. with artillery!