Does this bulbous bow make sense? - USNS Navajo (T-ATS 6)

An article in gCaptain this week: Bollinger Shipyards Christens Lead US Navy Towing and Salvage Ship, USNS Navajo (T-ATS 6)

Won’t the bulbous bow get in the way of pushing operations? Or is the bow fendering ment for something else?

No it won’t. It is not a push boat; it’s an ocean salvage vessel designed to tow astern.

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It’s not a push tug. It’s not even a barge handling tug.

I have no idea what that fendering could be intended for.

The Navajo Class is based on on an AHTS design (VS 4126 Mk IV) from Vik Sandvik (now Wartsila):

Some modifications were made to US Navy demand.
Maybe the bulbous was changed as one of those?
The bow fender could be a “leftover” from the original design.

The original VS 4126 design is from late 1990s, but modified versions have been built as late as 2016 at least:

A image search turns up this vessel:

Built in year 2006
Design is : VS 4612

Different design number but has both bulbous bow and bow fendering.

Bow fender and Bulbous yes, but is it the same dimension as on the Navajo Class?
Maybe modified?

That is one of the Sealion’s D-class. Probably “Toisa Dauntless” while she was sitting at Selat Pauh Anchorage in Singapore, waiting for next assignment.
PS> I inspected here there for approval to tow a rig from Batam to China.

Another picture of Toisa Dauntless, this one at Eastern Anchorage, Singapore:

Correction, it is probably “Toisa Defiant” (Blt. 2006):

It makes sense in the way that we wouldn’t expect MSC to make smart decisions.

Why is there a pile of the ship’s mooring line on the dock next to the Bollard? Is it normal for ships to be christened with half the equipment missing? (off ship fire fighting, anchors, crane…)


Yes, that is normal. Christening can take place up to a year prior to delivery.

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Or months after the delivery.
It is a tradition to have a naming ceremony, but it is not a legal requirement.

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Well, around here it usually coincides with the ship launch, if a new-build. And the launch needs to occur in advance off lightning of all the systems. Hence the 12-month lead time.

4 posts were split to a new topic: Ship Launching Ceremonies

The Navy has considerable experience operating this type of vessel. Before the Navajo-class there was the Powhatan-class. I recall seeing them from time to time in the Pacific.

Seven built between around 1976 and 1980

The Safeguard-class: Four built between 1982 and 1884

The Cherokee-class, 29 built from 1938 to 1945.

The Coast Guard operated one Cherokee-class tug, the Tamaroa, I recall seeing her at the USCG base on Governors Island.


Here’s another:


22 built starting in 1942.

The Powhatan-class was designed mid-1970s, based on OSVs at the time:

A port beam view of fleet tug USNS POWHATAN (T-ATF-166) moored at the Naval Amphibious Base at Little Creek, Virginia. Photo: Don S. Montgomery

Looks similar to this one:

But more likely based on this one:

The first Norwegian supply ship, Sea Pearl (800 tdw, 3800 bhp), from Mangone Shipbuilding in 1971 to Bugge Supply Ships, Tønsberg.

PS> Mangone Shipyard was busy building AHTSs for Norwegian owners for a while after that:

The OP asks if having both bow fendering and a bulbous bow makes sense. I don’t see an issue but I’ve no experience on tugs of this type.

My point is that the Navy does have a lot of experience building and operating these vessels. There’s nothing in this tread that would explain what the issue with the design of this class of vessel.

Also - The Navy Towing Manual is well regarded amongst experienced commercial mainers in that sector.

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Looking at the photo and other profile photos and drawings it has the appearance of the bulb protruding past the fwd edge of the fendering, such that if you were pushing something with the bow fender you’d have already hit them with the bulb. Could be the angle of the photo, but looks like it to me.

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From this angle, the bulbous bow does not appear to extend forward of the prow. The “fender” is clearly designed to protect and not to be used for pushing.


The original VS 4126 design appear to have a shorter bulbous and bow fender, while those built later appear to have a more protruding bulbous, but lacks the bow fender.

Has anybody found the “As built” GA-plan for the Navajo-class T-ATS?

I’m sure it’s just the photo angle


Maybe the folks welding the bulb were using a metric tape measure and the folks working on the prow were using an imperial tape measure, because all the photos from the christening make it look a lot like that bulb is sticking out.


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“The hull form of the T-ATS has a bulbous bow that will enable improved seakeeping capabilities and enhanced fuel efficiency”

The bulbous bow doesn’t show as an item being altered from the VS 4126 IV design according to this: (Page 8 & 9)

(Nearest to a GA-plan I have found)

It may well have been changed from the early version of this designs, though.

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