Page 39: of Marine News Magazine (March 2017)

Pushboats, Tugs & Assist Vessels

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Many established businesses have used the same surveyors for years. They have a good relation- “ ship with the surveyor and get a good report from him. If your surveyor is part of a company that has more than one surveyor, ask for someone else the next time. New eyes on your vessel will help.

A Survey Primer max depth) where the internal fram-

As you begin to survey your towing ing is intact and connected? Do any of vessels for Sub M, these are some of the set-ins exceed 25% of the beam in the areas that you should be taking a a transversely-framed bottom?

harder look at: • Structural Members: Is there • Plating: What condition is your any bending, twisting, buckling, bottom plating in? How about the side crushing or other distortion of shaped shell? Bow plating or rake sheet? Stern or ? anged structural members (angles, horizontal plates? Tunnels? Is there channels, I-beams, etc.)? Is any distor- excessive corrosion, cha? ng, buckling tion of structural members associated or other deterioration? with wastage?

• Gauging: Have you done a • Coatings: What is the overall gauging of the hull? Pay attention to condition of the exterior coatings? suspect areas. What’s the steel like un- When was the vessel last bottom der your generators? How are the stern painted? What type of paint was used? tubes? Are there fractures? Have frac- Was the bottom paint approved for tures been repaired in the past? use in the US? • Doublers: Are there any dou- • Anodes: Do you have any? Are the blers on your hull? If so, where are ones there still effective? How long were they? Were you patching a hole, cov- the current ones there and will they be ering bad steel or putting them on as effective until you haul out again?

wear plates? What does the steel look • Propellers, Struts and Bearings: like on the inside? How many propellers are there? What • Set-Ins: Are there any sharp set- are the propellers made of? How many ins (where the plate forms an angle of blades? What size? How is the propel- less than 135o (2.5” depth/1’span) in ler ? tted to the shaft and what keeps it any direction or where internal at- there? Are there stress fractures in the tached framing is abruptly tripped? hub or on the blades? Are the blades

Are there any smooth set-ins (where damaged? How long have they been in the plate is set-in 1” deep/1’ span, <4” service? Are the tail shafts and bearings 39 MN

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