Tuesday, December 30, 2014

New Towing Winch Design

By Mark Edward Nero

More than a decade ago, Seattle-based Western Towboat Co. purchased a new towing winch from another Seattle-based company, equipment developer Rapp Marine (formerly Rapp Hydema), for a new tugboat Western was building at the time, the Gulf Titan. Since then, Rapp Marine has manufactured several towing winches for Western Towboat and a long-term working relationship has been maintained. In recent years, Western Towboat has increasingly moved toward building its own tow winches, but earlier this year the company began working with Rapp Marine on a groundbreaking winch prototype.

The two companies began talking about the project about eight months ago, Rapp Marine Northwest engineering and production manager Dan Markovic said.

"We made a preliminary proposal and they liked it," he explained. "We offered to work together on it, and we applied both Western Towboat's and our solutions into our design and engineering."

What makes the prototype winch different is the level of expertise that both Rapp and Western Towboat are pouring into it, Markovic said.

"They told us what features they would like to have on the winch, so we basically used their experience as the end user alongside our experience as the manufacturer and designer of the equipment. We believe that we came up with a great product for the towboat market," he said.

Western Towboat differs from some other West Coast towing companies in that they build many of their own boats and other equipment, as well as perform much of the maintenance on that equipment, as opposed to other companies that send their equipment out for repairs and maintenance.

"The people here, the guys that build the boats and build the winches also do the maintenance on them once they're done, so it kind of makes things easier for everybody to be able to maintain it once it's done, rather than have something designed by a naval architect or something that way," the company's co-owner, Ric Shrewsbury, explained. "Our guys are able to do more and more of that type of thing and redesign things so that it's easier to maintain afterward."

Shrewsbury said that although the prototype winch will be new, it'll include elements of past winch designs.

"We're using their drive system on a winch that we have built in the past and we're building it as a double drum winch this time," he said. "We've kind of redesigned the back end of one of their winches and, between our people and their people, are kind of redesigning this winch a little bit."

Shrewsbury said that his company likes to "take the best of all worlds" and use what works, with one example being offset pins.

"We like the offset pins so that we can wrap our chain right up under a tow wire," he explained. "If the tug has to carry around a 90-foot piece of three and a quarter inch chain or three-inch chain they can just wind that right on top of the drum rather than have that all over the back deck."

Regarding the Rapp Marine prototype, the main drum capacity is more than 3,200 feet of two-and-a-quarter inch steel cable, with an additional 2,700 feet of two-inch cable stored onto the smaller drum. The pull at the first layer is rated at 25 metric tons.

The Rapp four-motor hydraulic drive is equipped with three speed steps, providing speed range from 30m/min up to 124m/min.

"For our winch division, this product is unique," Markovic said. "This is the first one, and is custom made for Western Towboat.

The project consists of a sole prototype, and once it is perfected, Rapp plans to open it for sale to other customers.

"This is a huge winch," he says. "It's quite a project."

Under the agreement with Western Towboat, although both companies are putting in resources, only one will retain ownership.

"This is a Rapp product. Western Towboat is working with us but this remains Rapp property, 100 percent," he said. "We hope that many other winches will follow."

Rapp Marine has not talked about the cost of designing and building the prototype, with Markovic saying that his company will wait until a later date.

"We are putting a lot of our time into this deal that we are not charging. In order to calculate the cost, I think you would have to wait until the project is finished and then we will see where we are standing with that," he said.

As far as the completion date, it's expected sometime in early 2015.

"We've been working on it for quite a while because we have time," Markovic said. "Since we did not have to rush, we wanted to make a complete, 100 percent product. You'll never get to 100 percent, but we want to get as close as possible."

He said that taking the time to get things right is something that's very important to the success of the company's products and the company as a whole.

Rapp Marine, which is headquartered in Norway, has had a presence in the Pacific Northwest since 1980. It has been most involved in equipment for fishing fleets, but the company has also delved into other fields, such as scientific winches, workboat winches and tug winches. Rapp has recently delivered deck machinery for National Oceanic and Atmospheric Administration and Alaska Region Research Vessels, and has become a supplier of winches and deck cranes for Coos Bay, Oregon-based towing company Sause Bros.

"We understand that the winch is a working tool for the vessel; if the winch does not operate, the complete vessel may be out of action," Markovic said. "We pride ourselves in being flexible regarding customer's needs, so we don't offer 'shelf' products. Each of our winches is customized in a way to meet specific customer's needs."