Boatnerd Discussion Forum

Perhaps a double acting design might prove useful if Essar Minnesota gets its steel slab production going, ends up sending most of the slabs to Sault Ste. Marie for finishing, and decides to move them over water. See discussion here: http://newsearch.boatnerd.com/viewtopic.php?f=6&t=2483

[quote="sgrima"]
Another issues I noticed is that from what I can tell most, if not all, of these double acting ships are crude oil tankers. This observation leads to two conclusions; 1. The fact that all tankers now have to be double hulled probably helps with the operational characteristics of double acting ships. (The idea that since the hull is thicker it is better designed to break ice) and 2. the transport of liquid bulk cargos on the great lakes is relatively low and highly specialized. Tankers mostly don't carry crude but rather finished products, therefore they are smaller than their ocean counterparts. All the tankers on the US side are tug barges, which the reverts back to what I previously mentioned about the ITBs.[/quote]

I see what you are saying, but the first two DA ships are bulkers designed to carry nickel into and out of some Russian port (the name escapes me at the moment). My 2 cents on the reason for the lopsided number of liquid-bulk ships to dry bulkers would be purely economic, oil is more vital to have year-round than something like taconite or grains when there are available ground transportation options. Another thing I was thinking about was the fact that the DA ships are considerably smaller and beamier than any Lakes freighter, due in large part to their need to use mass to break ice channels, something which wouldnt fly on the Lakes.

From what I've heard and seen from friends in the coastwise ITB/ATB field, the tug/barge combination tends to lose much of its effective icebreaking power in heavy ice conditions, primarily because 1) The barge may be ice-rated, but is not designed to be an effective icebreaker and 2) If the tug is forced to tow the barge and rely on its own icebreaking capabilites, the amount of ice it can break is greatly reduced due to the loss of mass.

AFAIK, the only barges with significant ice breaking capabilities and ratings are being built for groups like Crowley at Gunderson and are being used for the USWC/Alaska route, so any lakes carrier wanting a similar capability would have to invest in a new technology/design anyway.

The U.S. side doesn't have a specific tax for ice breaking but the icebreaking services are paid for by taxes. Just as our taxes pay to keep the roads clear.

[quote="sgrima"]

The Coast Guard provides a free service and in the great lakes shipping its all about saving money. So if they can get a free service versus spending millions to build a new ship, I just don't see it happening. All new builds on the lakes have been ITB's and most of the tugs can do their own ice breaking. [/quote]

Maybe the american coast guard does it for free but I don't believe this to be the case on the Canadian Side. I know in 2003 or 2004 I was on the JD Leitch and we ran into mid feb for hydro. I was told that Hydro had put up a million bucks for ice breaking to keep the coal coming. We went through that in roughly 3 weeks and then went to the wall.

[quote="sgrima"] (The idea that since the hull is thicker it is better designed to break ice) .[/quote]

Double hull does not mean thicker steel in the hull - it means that the cargo compartment is separate from the actual hull of the boat. See here for an example: http://www.diamondvessels.com/printfriendly.php?page=380&news=4

[quote="sgrima"]The Michigan/Great Lakes ITB is one in particular, also as previously mentioned Great Lakes Fleet redesigned many of their ships to have reinforced hulls to break ice.
... 1. The fact that all tankers now have to be double hulled probably helps with the operational characteristics of double acting ships. (The idea that since the hull is thicker it is better designed to break ice) [/quote]

Couple items, when I was on the Mackinaw we spent a lot of time escorting the Michigan/Great Lakes through the Straights, she did so poorly we tried to use the winch to pull her through. Not all tug barges are good ice breakers. It all comes down to power and hull design. Also, a double hull tanker does not mean is has an ice strenghtened hull.

Many ships on the Great Lakes have bee designed to break ice already. The Michigan/Great Lakes ITB is one in particular, also as previously mentioned Great Lakes Fleet redesigned many of their ships to have reinforced hulls to break ice. Also the Coast Guard takes its commitment to keeping the shipping lanes open during the winter pretty seriously, they often bring a few cutters from the East Coast to help with ice breaking operations. (most of the time by mid winter the smaller cutters need to go in for repairs).

The Coast Guard provides a free service and in the great lakes shipping its all about saving money. So if they can get a free service versus spending millions to build a new ship, I just don't see it happening. All new builds on the lakes have been ITB's and most of the tugs can do their own ice breaking.

Another issues I noticed is that from what I can tell most, if not all, of these double acting ships are crude oil tankers. This observation leads to two conclusions; 1. The fact that all tankers now have to be double hulled probably helps with the operational characteristics of double acting ships. (The idea that since the hull is thicker it is better designed to break ice) and 2. the transport of liquid bulk cargos on the great lakes is relatively low and highly specialized. Tankers mostly don't carry crude but rather finished products, therefore they are smaller than their ocean counterparts. All the tankers on the US side are tug barges, which the reverts back to what I previously mentioned about the ITBs.

Thanks for the replies -

I would think that despite the initial costs involved with evaluating and building one or even a small fleet of these vessels could exceeded by the revenue created by offering year-round service and down time inside or outside a port awaiting an icebreaker.

I guess the other half of the problem would be trying to operate the locks.

If fuel prices rose to the point that truck/rail ferries, steel coil/slab carriers, and/or containerships became competitive vs. land modes of transport in the Great Lakes region, it would be beneficial to companies involved in such business to be able to provide year-round service. It would seem like a double-acting vessel would work well for that purpose, enjoying both the benefits of a fuel-efficient bow design for use in open water with heavy icebreaking ability astern when necessary.

Older railroad ferry ships such as the cheif were capable of breaking ice for other ships and for itself as well

There was a good write-up in the December 2003 issue of Ships Monthly. The two tankers that you show, Tempera and Mastera operate from the Primorsk oil-terminal (north of St. Petersburg, Russia) to Finland. In the article the captain stated that they had gone through 15-metres of ice with-out icebreaker assistance. Though the process is stop-and-go in such conditions.

I don't think there would be a demand for such a cargo ship on the Great Lakes. Most of today's ships were designed for operation in ice and with the 1970s Winter Navigation Demonstration program, the industry learned a great deal about moving cargo on the lakes in the winter.

Such vessels would be expensive to build and current economic conditions don't justify such expenditure.

Hello - I'm a new member to the boatnerd forum and recently moved from New York City to Buffalo. I'm slowing getting myself familiar with the ins and outs of Great Lakes shipping and have had a question for those more experienced and knowledgeable in the whys and why nots of Lake shipping:

Do Double Acting Ships have a future on the Great Lakes?

To clarify, a double acting ship is either a liquid or drybulk vessel which is designed to operate as a standard vessel (eg bow-forward) in open seas but when faced with frozen ports or sea ice the vessel swings around and moves astern and uses a icebreaker-style Stern design to break through the ice.

There are several examples of these types of ships in operation in areas like Scandanavia and in the near-perpetually frozen Russian arctic ports, and they seem to be holding their own thusfar despite the rigors of their work. They are all-new technology ships, utilizing stern-mounted azipods for propulsion, can make in the area of 13 knots and are expected to break through miles of sea ice into and out of their ports of call without icebreaker assistance.

Here's a wikipedia link for a better explanation and links: http://en.wikipedia.org/wiki/Double_acting_ship
==

So, ignoring the obvious "who's gonna pay for this high end
technology" question, does anyone here think these types of ships have a future on the lakes? I assume lake ice thickness and composition is much different than ocean ice, but is it even feasible to operate what is essentially a cargo-carrying icebreaker on the lakes?

Thanks for your thoughts!
Mike

Some pics: