Arctic Patrol Cutter, State of the Art

Recently the Commandant mentioned the possibility of a requirement for an Arctic Patrol Cutter. This was the first time I had seen official mention of something less than a full fledged icebreaker for arctic patrol.

There has also been a recent DOD report which referred to the “limited inventory of ice-capable vessels.”

Thought there might be some interest in seeing similar ships the rest of the world is producing. I’ll go from smallest to largest:

Danish Knud Rasmussen class, two ships Knud Rasmussen and Ejnar Mikkelsen, completed 2008/2009. References and analysis here, here, and here:

Displacement: 1,720 tons
Length: 72 m (236 ft 3 in)
Beam: 14.6 m (47 ft 11 in)
Draft: 4.9 m (16 ft 1 in)
Propulsion: 2 x MAN B&W Diesel ALPHA 8L27/28 generating 2.720 kW each
Speed: Less than 17 kn (31 km/h)
Range: 3,000 nautical miles (5,600 km)
Boats and landing
craft carried:
1 x SB90E for Search and rescue, 1x 7m (60 HP) RHIB, 1 x 4.8m (45 HP) RHIB
Complement: 18 + aircrew and transients (Accommodation for up to 43 in total)
Sensors and
processing systems:
1x Terma Scanter 4100 surface and air search radar
3x Furuno navigation radars
SAAB CEROS 200 radar and optronic tracking system and CWI illumination radar
Armament:(See notes below) 1 x 76 mm Gun Mk M/85 LvSa
2 x 12,7 mm Heavy Machine Gun M/01 LvSa
RIM-162 Evolved Sea Sparrow Missile surface-to-air missiles
MU90 Impact ASW-torpedo
Aviation facilities: Aft helicopter deck, no hangar

This class is intended to patrol west of Greenland. It replaces some much smaller ice strengthen patrol vessels, about the size of the Fast Response Cutter, that appeared to be trawler based, the Agdlek class. They are a great improvement over their predecessor, and if we had more infrastructure in terms of a base and an airstation in the Arctic, they might be useful. But the range (3000 nmi) and, to a lesser extent, speed (17 knots) limitations, and the fact that they don’t have a hanger for an embarked helicopter, probably make this type of vessel unsuitable for our purposes.

The hull was reportedly designed to break the normal 40cm (15 inches) sea ice and 70cm (28 inches) of hard fjord ice. In service broken ice was ingested by the engine cooling seawater intakes, so some redesign may be forthcoming. That might be a consideration for our own design.

They do have some worthwhile features. Boat davits are behind movable screens to prevent boats and davits from collecting ice and there is a stern gate and compartment under the flight deck for deployment of a 12 meter boat.

The armament listed is what the ships are designed for, but these ships use the StanFlex system that allows the quick replacement or substitution of armament or special equipment like cranes, so, while the sensors and firecontrol systems may be on board, normally the only weapons are the .50 cal. machine guns, minimizing crew requirements.


Canadian designed New Zealand’s “Protector” Class OPV, two ships, HMNZS Otago and HMNZS Wellington, completed 209/2010. 1,900 tons, 277 ft, 22 knots, 6,000 miles @ 15. Apparently very cheap to build. The design would probably not meet the American Bureau of Shipping (ABS) Rules for Building and Classing Naval Vessels that were applied to the OPC because it has all three generators in one compartment (I haven’t seen the rules, but I would presume that is a no-no).

This class reportedly as built, came out over its design weight, and its icebelt is lower than intended with respect to the waterline–with acceptable limits, but it will preclude adding any additional weight.


The Danish Thetis class, four ships, HDMS Thetis (F357), HDMS Triton (F358), HDMS Vædderen (F359), and HDMS Hvidbjørnen (F360), completed 1991-1992. Larger than a Hamilton class but smaller than the new National Security Cutter, they are a relatively simple design capable of breaking 80 cm (31 inches) of ice.

Displacement: 3,500 tons full load
Length: 112.3 m (368 ft 5 in)
Beam: 14.4 m (47 ft 3 in)
Height: 37.0 m (121 ft 5 in)
Draft: 6.0 m (19 ft 8 in)
Generators: 3 x Detroit Diesel GM 16V 7163-7305, 460 kW
1 x Detroit Diesel 6L-71N 1063-7005, 120 kW (EMG)
Propulsion: 3 x MAN B&W Diesel 12v28/32A-D à 2940 kW (3990 HP each), single shaft
1 x Brunvoll azimuth thruster (800 kW)
1 x electrical Brunvoll bow thruster (600 kW)
Speed: 21.8 kn (40.4 km/h)
Range: 8.700 nmi (16.112 km) at 15 kn (28 km/h)
Endurance: 60 days
Sensors and
processing systems:
1 x Terma Scanter Mil 009 navigational radar
1 x Furuno FR-1505 DA surface search radar
1 x Plessey AWS-6 air search radar
1 x SaabTech Vectronics 9LV 200 Mk 3 fire control system
1 x SaabTech CTS-36 hull-mounted sonar
Thales TMS 2640 Salmon variable depth sonar
FLIR Systems AN/AAQ-22 SAFIRE thermal imager
Electronic warfare
and decoys:
1 x Thales Defense Ltd Cutlass radar warning receiver
1 x Thales Defense Scorpion radar jammer
2 x Sea Gnat launchers (for chaff and flares)
Armament: 1 x 76-mm 62-cal. OTO Melara Super Rapid DP
7 x 12.7 mm heavy machine guns
4 x 7.62 mm light machine guns
1 x depth charge rack and MU90 Advanced Lightweight Torpedo for anti-submarine warfare
Aircraft carried: 1 x Westland Lynx Mk.90B helicopter
Aviation facilities: Aft helicopter deck and hangar

It’s a bit unusual in having three main engines and only a single shaft. To compensate for the lack of propeller shaft redundancy it does have a large drop down 800KW (1072 HP) trainable thrust unit for loitering and “get home” power. Like the smaller Knud Rasmussen class above, it uses the Danish “Stanflex” system allowing relatively rapid change out and augmentation of weapons and equipment like cranes. They have a relatively small crew of 52 but accommodations for 101.

Looks like when not patrolling the Arctic, a vessel like this could be useful on ALPAT.


The Norwegian Svalbard Class, one ship, KV Svalbard (W303), commissioned 2001. Really a small polar icebreaker, virtually the same size as the old Wind Class and almost 50% larger than the NSCs.

Displacement: 6375 tonnes
Length: 340.2 ft (103.7 m) (overall)
292 ft (89 m) (waterline)
Beam: 62.6 ft (19.1 m)
Height: 27.2 ft (8.3 m)
Draught: 21.3 ft (6.5 m)
Propulsion: 4 x 3390 kW Rolls-Royce Bergen BRG-8 diesel generators
2 x 5 MW Azipod electric motors
Speed: 17.5 knots (20.1 mph; 32.4 km/h)
Complement: 50 (20 Officers and 45 Other Ranks split into 3 shifts with 2 shifts on board at any one time)
Sensors and
processing systems:
EADS TRS-3D /16 ES with IFF
Armament: Bofors 57 mm, 12.7 mm
Aircraft carried: Capacity for two helicopters; one Lynx carried initially, NH90 from 2009
Notes: Cost: 575 million NOK (80 million USD), radar and helicopter not included

Perhaps more icebreaker than OPV, this looks like the current upper limit for this type.


The Norwegian Coast Guard also has three 3,200 tons ships of the Nordkapp class built in the 80s that are said to be “capable of ice browsing.”


Of course the Coast Guard is not without some experience in this area. USCGC Northland (WPG-49)USCGC_Storis (WMEC-38). Related posts here and here.

Cutter Northland

24 thoughts on “Arctic Patrol Cutter, State of the Art

  1. Chuck,
    If I were the US Coast Guard, I would go with a modified version of the Knud Rasmussen-Class Ocean Patrol Vessels. I would lengthen it to allow for a hanger to accommodating helicopters and UAV’s I would also include the capability for a stern launch ramp as well. The second choice would be the Svalbard class Icebreaker as well.

  2. ‘The Norwegian Svalbard Class”

    Could there be some harbinger of the future in the photo? W303. Looks like a former U. S. Coast Guard hull number. (Tupelo was W303)

  3. (For the time being let’s assume the USCG doesn’t have funds to buy a new cutter class).
    The USN could buy the design, tweak it for USN compatibly and bid it out for construction. Many second tier yards would jump on series production. If the Canadians, Kiwis, and Danes can do it why can’t the USN?

    The CASR analysis is good and shows the problems which the Canadians have buying ships. The ability to easily up-gun this design using Stanflex is something which should put LCS to shame. And its good boat handling arrangement may even point to its use as a mothership (especially IVO recent discussions about a ship to support NSW or NECC? N.B. the sideports for RHIBS with davits and a modern crane!

  4. In view of the fact that there are no Navy or Coast Guard airstations on the North slope, West coast of continental Alaska, or even the Aleutians any more, it would seem a good idea to provide what ever Arctic Patrol Cutter we build with robust helicopter support facilities, making these ships essentially mobile seasonal air stations.

    All these ships are beamier than the Oliver Hazard Perry (FFG-7) class ships which can hanger two H-60 helicopters. The Perrys’ beam is 45 feet. Of these four classes the least beamy is the NZ Protector which is a foot wider. It should be possible to provide a two helicopter hanger on even a relatively small Arctic Patrol Cutter. If they have room for two H-60s they should also have room for two H-65s and UAVs.

    To me, the Thetis seems a good size for the environment, and because of its length, it manages a decent speed on less than 12,000 HP. Given 24,000 HP (NSC diesel engines are over 21,000), a similar hull should be good for over 25 knots. I would like to see a similar ship with azipod style diesel electric propulsion that would allow loiter or slow cruise on generators alone and a hanger for two helicopters.

    Going to something like the larger Svalbard makes sense if the Coast Guard needs the additional icebreaker capacity which is certainly a possibility. She has 50% more HP than the Wind class (18,000 vice 12,000) so should be capable of some serious icebreaking. (Mackinaw has 9,119.) Bumping the HP enough to give her a speed over 20 knots would give her more HP than the Glacier (she had 21,000). (Enough to get in trouble?) It would also likely be a lot more expensive to operate than the smaller ships.

  5. What role would the NSF have with the patrol cutters? They would have to be included. That is where some of the money would come.

    • They pay for icebreakers because they do scientific research. Will the Arctic Patrol Cutters devote a substantial part of their time to scientific research? I had just assumed they would be doing conventional CG missions.

      • I don’t know if I would assume anything. If the Coast Guard can send a 125′ on an arctic scientific expedition as it did with Ed Smith, and ice breaking capable cutter on patrol would have some research capability. I think they should some ability to accommodate some scientists, if for no other reason than to keep the furor from the Congress at bay.

        The Coast Guard has a long tradition and history of combining arctic patrols with scientific research, plus it is good PR.

      • True, for a start they could hand over the ice-capable ships they have now, so that we could make them multi-mission. But year to year multiple agency funding is not reliable.

  6. I forgot to say, that the ice classing was not needed for USN purposes, but the design was a good one nonetheless.

  7. Pingback: Got Icebreakers? Show Me the Money! -

    • Take note that in the several seconds preceding touch-down, the rolling subsided considerably. When the rolling was at its worst, it was pretty obvious the pilot was just trying to hold station without the ship coming up and swatting the helo out of the sky during one of those rolls.

      The overall take-away on this video for me is: While this could be done if absolutely necessary, it shouldn’t be thought of as commonly acceptable.

      It wasn’t until watching this video that I realized how tall and beamy these are in relation to its length. Almost might as well be a cork from a champaign bottle in those seas…

      • Yes Bill this is why we don’t send 270s on ALPAT, These are relatively small ships, the smallest I considered. The other thing here, is that the flight deck is all the way aft. Having the flight deck nearer the center of pitch would be desirable. Putting it all the way aft means the amplitude of vertical movement is maximized for any degree of pitch, Areas near the center of pitch are in high demand. We would also like to put the davits, the bridge, and the living spaces there.

      • 210 works in the Bering Sea – CONFIDENCE sailed there for 17 years. Yes, you have to exercise good seamanship. There are issues about endurance. And yes, I know the problems – I was on CONFIDENCE when she took a 65 degree roll enroute from Kodiak to Hawaii.

        270s have design issues which limit their seakeeping. Have since they day they were launched. Remember the Bear’s first deck gun being ripped off?

      • @David Ackerman, I also served on Confidence when she was homeported in Kodiak and there is no doubt they can do useful work in South East Alaska. After all, we have 110s in Alaska. Still not the best ship for operating in the Aleutians or in the higher latitudes where we seem to be showing greater interest.

        It appears the Alex Haley is a good choice for now. Unfortunately the CG seems to have forgotten that the OPCs (Offshore Patrol Cutters) are not just replacing 13-270s and 14-210s they are also replacing the Alex Haley, Acushnet, Storis, and two 210s that have already been transferred to the Sri Lankan and Colombian Navies. That’s 32 ships not 27.

  8. Pingback: New Zealand’s “OPC” (OPV) in Action | Chuck Hill's CG Blog

  9. One comment on a single propeller shaft on Danish Artic ships. – That is what sailing in ice required until we got the later azimut propellers – One propeller protected by fins just forward of the propeller – And it has always worked. A newer design will take into account what is now available . And price of build not taken into account – US will normally accept to pay in dollars the same amount of what we in Denmark pay in kroners for same function.

      • Yes I got the impression that you liked the Thetis-class. I believe the first is very soon going to have a new hangar, to take the MH-60R coming soon. With harpoon under the belly, not “bear trap”..

        On the Knud Rasmussen class I can ad that they now sail with the 76-mm OTO Melara Super Rapid permanently – As will number 3 in the class, which is now being fitted out (HDMS Lauge Koch). My feeling is that there may be a more practical reason to fit the 76 mm – that is stability. Arctic ships will have to have a good reserve stability to cope with ice on decks and superstructure – this reserve stability would make them feel “stiff” – some extra weight high up would help that situation and make them more comfortable. Number 3 will have more ice resistance built in, and a dome on top of the radarmast. They will al have special sonars for hydrographic surveying. When they are in a an area, they might as well do some mapping – the area is not the best covered in the world.

        On the hangar for Knud Rasmussen-class – my opinion is that a zip might be found in the steel drawings, to cut and ad the few meters for hangar.

    • Single shafts were a common feature on CG cutters until the 327s were built in the early ’30s. Then they reemerged when the 255s were built during WWII.

      The USN FFG-7 class were also single screw ships as are I believe all of our submarines.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s