Thursday, July 29, 2010

Italian Chariots

Slow torpedo type SLC (Maiale)
First developed in 1935 the SLC became famous as the 'Pig' ("Maiale") human torpedo carrying out several successful attacks on Allied shipping in the Mediterranean. The effectiveness of these tactics led the British to copy the design, developing the Chariot (see separate post)
The craft consisted of a 533mm (21') electric torpedo with crewmen sitting astride it. The fairings contained tanks and extra oxygen, and the crew wore basic dry suites. The attack mode was to come close to the target port by submarine or larger ship. Maximum range for the Pig was 15 miles so the start point would likely have been within 7km of the target. For maximum surprise attacks were timed for moonless nights and efforts were made to eliminate bubbles from the divers. The warhead was mounted in the nose and was detached under the keel of the target. Some versions carried a twin charge.
The craft was employed by Italy's famous X-MAS combat diver unit, widely seen as the forerunner of all modern combat diving special forces (SBS, SEAL/UDT etc). The Pig is truly the grandfather of most modern wet-subs.

L - 6.7m, W - 0.533m
Speed: 2kts submerged (max 4.5kts)
Warhead: 240 - 300kg depending on version

Slow torpedo type SSB
Follow on from SLC, the SSB never saw combat arriving too late, but was operational on both sides during the period. The crew sat semi-enclosed in a better faired cockpit.

A note about Cos.Mo.S Spa ('Cosmos')
Cosmos is probably the most famous military wet-sub / midget sub manufacturer in the world. The firm originated in the 1950s when an ex-X-MAS member (WWII Italian navy special forces), Ing. Pucciarini started to build wet subs for civilian and military use.

Despite Cosmos' fame it is quite difficult for amateur researchers (like us!) to put an authoritative timeline of version history together. The company was generous with sales material but secretive about customers and had several reported orders turn sour for one reason or another, resulting in much misreporting of operators. Added to this many of its customers received extensive upgrades to their vehicles, both by the manufacturer and as local modifications. Therefore two vehicles with the same version designation but operating with different countries may look quite different, and two vehicles of different models but different state of upgrade can look virtually  identical.

Amid the secretive and misreported sales history of the company it's common for the sales record of Cosmos to be somewhat overestimated. It's said that they produced several hundred vehicles, which is almost certainly incorrect. We are slowly piecing together the operators inventory - if you have additional information please do not hesitate to contact us via the comments top this post.

In the mid-1980s Ing Pucciarini sought retirement and the firm was eventually sold to infamous Chilean arms dealer Carlos Cardoen. In the late 1980s Cosmos had been negotiating a substantial sale of subs to Iraq. With the end of the Iran-Iraq war this stalled, made further difficult for Saddam Hussein's rapid fall-out with the West and Gulf War 1. Cardoen was not deterred and the deal morphed into the infamous "Oil-for-Food Program " scandal. Unbelievably Cosmos was trying to secretly supply Saddam Hussein with midget subs. Eventually in the early 2000's the Italian Government closed the company down. Some of their unsold craft which were on-hand at the time 'disappeared' - operator unknown.

The company's reputation has been soiled, but the reputation of their vehicles has not. They are generally speaking very well designed, simple to operate and maintain, and most of all fit for purpose. There are very popular among operators. The unsavoury demise of Cosmos has however opened the way for a number of new small/wet-sub manufacturers to fill the void, with significant new players in South Korea, UAE, Sweden and Indonesia springing to mind.

Contrary to popular perception, Italian naval special forces have never operated Cosmos wet-subs.

Ippocampo (Sea Horse)
The Sea Horse was the first of a family of wet-subs which were the predominant designs of this type during the cold war - the CE2F family (see below). The Sea Horse predates the formal establishment of the company, having been built and tested in 1950/51.

Pucciarini wanted to market SLCs (as they were then known, SDV in current terminology), as tourist and sports vehicles. The design was based somewhat on the SSB design concepts but without a warhead nose. Overall the craft was much shorter than the SSB with a relatively larger portion of the hull dedicated to crew accommodation. Unlike the SSB and equivalent British Chariot Mk.II which attempted to minimise the size of the crew compartment, the Sea Horse had a large open cockpit for easy access.
In an unlikely move Pucciarini employed a small petrol (/oil) engine rather than a electric motor to reduce operating costs. This did however pose operational complexity requiring an air hose to supply the engine. This used a buoy to both mark the subs position and keep the inlet above water. This arrangement made the craft unsuitable for clandestine military operation.

Early Cosmos Civilian craft
The Seahorse was marketed in USA by scuba diving company Healthways. Initial version had a gas engine but soon electric versions were marketed.
Healthways Seahorse-II. Photo Life

In generall the gas powered craft were known as Seahorse and the electric ones as Seahorse-II although both names appear to have been applied as generic terms rather than to specific models. One version appears to have been marketed as "Sea Shark".

Cos.Mo.S.  Seahorse-II (military)
The USN SEALs/UDT purchased several Seahorses from Cosmos, and possibly from Healthways. These were generally similar to the civilian models although they underwent various modifications, both local and manufacturer led. Records on these craft are sparse - see separate post on US SDV (Swimmer Delivery vehicle) history (**WIP**).

An enlarged Seahorse-II capable of carrying up to four divers. Used by USN SEALs for training. Some onward-supplied to Pakistan where they were operated alongside CE2F type. (**WIP**).
Cos.Mo.S. CTF2
Training version of CE2F (see below), this type was only operated by Taiwan with 2 units sold (some sources say 8 but that includes the CE2Fs, see below). Now retired. The craft used an oil (petrol?) engine fed with air via a folding snort mast with ball-valve. This arrangement made it cheap to operate but unsuited to combat operations where the mast limited depth and compromised stealth.

Cos.Mo.S. CE2F series
The classic cold-war SDV, the CE2F was produced in several variants and exported to several countries. Models were designated according to maximum operating depth in meters - /X30 = 30m etc. X30, X60 and X100 versions sold. Provisional table (subject to update):
  • Taiwan - CE2F/X30
  • Greece - CE2F/X60
  • Columbia - CE2F/X30 later upgraded to X60
  • India - CE2F/X100
  • Pakistan - CE2F/X??
  • Argentina - CE2F/X60
  • Egypt - CE2F
  • South Korea - CE2F/X60
 Additionally some sources report Philippines as operators.
Armament consisting of limpet mines, charges or even small 'micro-torpedoes' is carried in a belly-pan beneath the cockpit. The /X100T version was the most advanced type marketed showing the final evolution of the design.
L - 7m
Weight : 2.1 t
Maximum depth : 100 m
Range: 50 miles
Speed : 4.5 kts (underwater)

Although Cos.Mo.S no longer produce subs, the design has influenced several manufacturers, notably South Korea's Vogo whose SDV-300 and SDV-340 designs are somewhat similar in appearance.
Cos.Mos.S. CE4F and CE6F

Unbuilt designs for four and 6 divers. The CE2F could carry three divers but standard load is just two as per the WW2 Maiale.

Maritalia 3GST9
L - 9.65m
Displacement - 29t
Armament: Limpet mines deployed by frogmen, or, 2 lightweight torpedoes in tubes, or 48 122mm rockets. 6 Mini-torpedoes for harbour defense against SDVs.

Tuesday, July 27, 2010

Small Navies' indigenous infiltration craft

Collection of wet subs, midget subs and other infiltration craft developed in smaller navies, or countries with few designs in this field.

KTBA series wet subs, Indonesia
Indonesia has a capable combat swimmer force, the Kopaska special diver unit, who operate locally produced Sub Skimmer wet subs (a British design, see separate posting).

The Kendaraan Tempur Bawah Air (KTBA) series of indigenous wet subs have recently entered service after experimentation and testing. Early models, -I and -II, are twin seat affairs with externally mounted diver propulsion devices. The larger -III and -IV versions have twin in-built propulsors on the rear hydroplane and can carry 3-4 combat divers at 3-4kts submerged. All designs are easily recognised by the distinctive bow fairing with shark-gills and upright windscreen (often without glass). Materials are predominantly fibreglass.

The KTBA series have been tested operating in conjunction with the Indonesian Navy's Type 209 submarines (Cakra class).

Emirates Marine SDVs, UAE
- Class 4, 5, 6 & 8
Also possibly called Barracuda in some markets.

An extremely advanced wet sub design in service with UAE Navy. May be exported.
L - 9.3m, W - 1.15m
The crew are fully enclosed under sliding canopies, and are aided by Sonar, GPS etc. Batteries are stored in side pouches and the system is propelled by a single shrouded propeller.

The Class 6 and 8 versions are reported to have a diesel engine for surface running at up to 20kts, and a retractable periscope/sensor mast.
There are reports of this craft being exported to Taiwan.

Class 5 type. Photo via

Wednesday, July 21, 2010

British SF water craft

MSC 'Sleeping Beauty'
Motorised submersible canoe (MSC) first developed for SOE in WW2 and used in sabotage attacks similarly to X-Craft. The design accommodates a single frogmen, although on occasion two crew were employed with the second frogmen lying on the bow. Various configurations were tried with the greatest external differences being the positioning of the hydroplanes, which were initially aft but often moved forward. Some versions had hydroplanes both fore and aft. Small trim tanks were assisted by longitudinal movement of the batteries. Control of the craft was very difficult.
Modified MSC with bow fairing and bow planes added. Photo:

The craft was employed by SBS after WW2 and can be argued to one of the main forerunners of the current SDVs.
L - 4m
Diving depth: <20m

Excellent further reading . Additionally this picture is very interesting (Welfreighter site)

A relatively unsuccessful design, the Welman single seat midget submarine was developed in WW2 for sabotage missions. Over 100 were produced but only one combat mission was run. Among the deficiencies, amazingly the sub lacked a periscope. The warhead was mounted in the nose much like the Chariot (see below).
L - 6.25m (inc warhead)
Speed -  3kts
Operating depth - up to 30m 

Chariot Mk. I
Directly inspired by the Italian slow running torpedo (SLC-200 "Maiale") which was successfully employed against the British fleet in the Mediterranean in WWII, the Chariot Mk.1 followed the same general arrangement but used a British 21" (533mm) torpedo as the base. Due to the R&D advantage of a salvaged Italian example, the first craft were operational within 7 months of program initiation in 1942. Despite this much experimentation was required to ready the tactics and operating procedures to employ the craft operationally - in particular RN Chariots typically operated in much colder environments than their Italian counterparts.

The superstructure was slightly more substantial than the SLC, with a more faired rear locker. Performance was comparable.

L - 6.8m
W - 0.88m (body 533mm)
Speed - 2.5kts
Operating depth - up to 27m

One notable operational difference was that the British supplied the frogmen with pure oxygen which can be fatal, and probably cost the lies of some crewmen. Otherwise employment was very similar to common Italian X-MAS tactics with transit to the target area by means of large storage bins bolted onto the outside of submarines. See more details on the Italian SLC HERE. Plans HERE
Photos via Top: Chariots in transit containers aboard a submarine. Lower: Running awash.

Chariot Mk. II
Almost before the Chariot Mk I was operational, work was already underway on a much improved craft with the crew sitting inside the chariot rather than astride it. The crewmen sat back-to-back, a layout subsequently echoed in some other types. The warhead was still in the nose and general operations were conducted in the same way.

Kept a secret for many years, the story of the Welfreighter spy/saboteur infiltration craft has only recently become known and is still clouded with some uncertainty. Developed in WW2 for the Special Operations Executive (SOE), the Welfreighter was in concept a small midget submarine which, when on the surface, had the appearance of a small fishing boat allowing it to run on the surface during most of the operation. In many ways the design is a precursor to some North Korean infiltration craft which use similar deceptions.

The craft had a diesel engine for surface running and used electric motors, driving separate props, for underwater operation. A protracted trials period with some friction between SOE and Naval architects (the craft was not designed by the navy and did not fit navy norms), created several iterations with successively better performance. A key performance field was range, allowing good operational autonomy.

L - 11.2m
Speed: 5-7kt surfaced, 2-3kt submerged
Range: About 1,000 miles (longer in ferry mode)
Underwater endurance: Up to 40hrs with 6 persons. About 15 miles range on batteries.
Load: 2-4 agents and approx 2,000lb of stores (depending on mission/version)
about 25 boats were built but it does not appear to have been used in any operations and does not appear to have been in service post war.
Almost certainly the best internet source for this craft is:

Cockle Mk II Canoe
Made famous by Operation Frankton in WWII when six Mk IIs were employed in a daring commando attack on the port of Bordeaux (See Cockleshell Heroes), the Mk II is two-man folding kayak design allowing transit within an unmodified submarine with exit via the main hatches. The canoe is made of canvas with a wooden frame. Although less sophisticated than submersibles, canoes can offer some advantages in certain mission profiles where minimal draught (ideal for shallow rivers), ease of crossing land obstacles and less training are required.
L - 4.6m

16m VSV
Vosper-Thornycroft (VT) Halmatic built at least one 16m long very slender vessel (VSV) in late 1990s to a modified Lurssen design similar to those operated by Indonesian Customs. The company is now closed and there are reports of the craft being retired.
In concept the VSV is a wave-piercing design capable of high speeds (est 60kts) even in heavy seas. Similar VSV designs are in service with US special forces but no military appears to have adopted them in large numbers. In service with the SBS the craft is suitable for insertion and boarding duties.

Stealth 'Beauty'
Produced by VT Halmatic shortly before the company's demise, this craft is rumored to have replaced the VSV although augmented is more probable. The craft's designation is not known and some observers have labelled it the Beauty due to its clean lines. The hull is not wave-piecing and features stealth lines.
The rear deck is often covered, with a large tailgate aft for easy access. The working deck appears suitable for swimmer vehicles (such as Stidd DPDs), canoes or dingies.
It is possible that the craft is semi-submersible. At least two craft have been delivered.
Additional good photos: HERE and HERE

***Works in progress***

SBS Canoes
SSK-96 Subskimmer
Sleds etc

****Foreign craft used by British SF****
Klepper Canoe (Germany)
Stidd DPD (USA)
Fabio Buzzi MIL-50 (Italy)

Monday, July 19, 2010

Lost in Plain Sight: GIMIK and OSS Project NAPKO

This was one of World War Two’s longer-running mysteries, finally solved. This is one of a pair of two-man submersibles that were designed and built for the OSS (Office of Strategic Services, the U.S. wartime intelligence agency) in Connecticut in May, 1945. Code-named “GIMIK,” these vessels were the infiltration assets for a clandestine operations program devised and headed by Colonel Carl Eifler called Project NAPKO. NAPKO’s purpose was to recruit and train 55 Korean Americans and Korean Prisoners of War for infiltration into Japan to collect intelligence and conduct sabotage in advance of Operation Olympic, the planned U.S. invasion of the Japanese home islands in late 1945. Korean POWs were targeted as Korea was at that time under Japanese occupation, and Colonel Eifler correctly believed that Korean nationals who had been inducted into the Japanese military, and then captured by U.S. forces during the Pacific campaign would be inclined to turn against their colonial masters in order to help shorten the occupation of their country.
NAPKO’s original plan called for three boats, however only two were actually built, costing $20,000 each. Gimik had an operating radius of only 110 miles, and was intended to be transported to its destination by a mothership to a point off the enemy coast, and then take its operator and a single infiltrator passenger ashore. When operating in the infiltration mode, the craft ran as a semi-submersible with its deck awash until reaching a point close to the landing area. Upon arrival at this point, the crew would submerge the empty vessel to a depth of up to thirty feet, where it could remain underwater for a period of up to three to four weeks while its crew was ashore carrying out their mission.
The two GIMIK boats were delivered to the OSS on June 10, 1945. Following delivery, they were used to train Project NAPKO crews at the OSS training facility at Catalina Island, off southern California over the summer of 1945. NAPKO’s Korean operatives repeatedly penetrated the harbor defenses of both Newport Beach and Los Angeles undetected, as well as landing agents at Newport Beach and San Clemente during their operational workups.
Preparations to execute NAPKO continued until the scheduled departure date of August 26, when Col Eifler and his teams were to depart for their overseas base, probably located at Kerama Retto, Okinawa. In summer 1945, Okinawa was the closest Allied-held territory to Japan; Kerama Retto had served as a base for both Japanese Army and Navy explosive suicide boat units. Following occupation, Kerama Retto served as a major advance support base for Allied forces in preparation for the upcoming invasion of the Japanese mainland.
After arrival at Okinawa, Eifler and his Korean agents would board a US Navy submarine and rendezvous off the coast of Japan with GIMIK and its mothership, which had been previously staged at Okinawa for the operation. At the rendezvous point, Eifler and another agent would board one Gimik boat, and presumably another pair would board the other boat. Japan’s surrender announcement on August 15, of course, put an end to NAPKO’s deployment.
With the end of hostilities, Gimik was forgotten and left in storage for a number of years, until it was found in 1972. Based on a magazine article from the mid-1980s, it was originally thought that the boat was found in Okinawa, however, recent research leads us to believe it had been in storage at the U.S. Naval Base, Newport Rhode Island. Because of its odd configuration, and a complete lack of documentation, it was thought to have possibly been a captured Japanese suicide boat, albeit one that really didn’t match the major Japanese types. The boat was restored and placed on display in the PT Boat collection at the Battleship Massachusetts, where it was displayed as possibly being a Japanese suicide boat, but heavily caveated with the fact that nobody really knew its identity. GIMIK remains on display at Battleship Cove to this day, now finally definitively identified.

Specifications and Technical Description:
Builder: Not definitely identified, but likely Electric Boat Company, Groton Connecticut
Length: 19 feet, 2 inches
Beam: 5 feet, 3 inches
Height: 6 feet, 9 inches
Weight: 3,650 lbs.
Engine: Gray Marine 4-cylinder gasoline type with Autolite spark plugs

Speed: Awash: 4.7 knots, Surfaced: 4.1 knots
Economical: 2.5 knots
Range: 110 nautical miles
Crew: 2-3
Cargo: 110lbs of equipment

The engine is sealed in a large steel pipe with an access hatch in the upper surface. The forward end of this pipe forms part of the aft crew compartment bulkhead. The fuel tanks are aft of the engine, while a small stack aft of the cockpit provides both air intake and exhaust for the engine. The large tube forward of the cockpit is the air intake for the crew compartment. The air pump is operated from a 3-belt V-type drive attached to the propeller shaft. Trim tanks are located at each end of the boat and can be operated while underway, the boat being designed to run awash. A muffler, by Maxim of Connecticut, is installed for quiet operation, and the cockpit is covered with a well designed hood of 3/8 in plexiglass. There are four small compartments in the bow and what appears to be piping running aft to the cockpit.

Photos: (top), Col Eifler's bio, The Deadliest Colonel (lower)

Saturday, July 10, 2010

-PROPER- amateur submarines

There are only handful of civilian fully-submersibles which are in size terms many respects comparable to military midget subs. Our greatest respect and secret envy to the people who get to build these, and all the other subs we've missed.
  • IC-1 Freya - Denmark
  • UC-2Kraka - Denmark - 12m
  • UC-3 Nautlius - Denmark - 16m
  • Spurdog - Netherlands - 20m
  • Euronaut - Germany - 16m
  • Malen - Sweden
  • SR93H Polaris-Delta - Hungary - 20m
  • SS86H Helen's Heart - Hungary - 7.5m

L - 12m
Built by Peter Madsen. Styled on WWII German U-Boat.

Photos: Flickr

Probably the best known civilian midget sub. Interesting features include 'diving helmet' cockpit and bottom mounted diving hatch below sail. Forward viewing windows positioned to look like torpedo hatches.

L - 16.01m W - 2.5m
Speed: 8kts
Built by Carsten Standfuss in Germany for wreck diving. Nearing completion. Website for lots more info:
Very large by civilian standards, the Euronaut is relatively sophisticated and heavily built, able to dive to an impressive 250m (test depth 320m). The sub will operate with a 5 person crew for up to 7 days before surfacing.

UC-3 Nautilus
L -17.7m, W - 2m
About the same size as the Euronaut, Peter Madsen's third submarine follows on from the Kraka. The sub became operational in 2009 and is employed in recreational diving. The hull features large port holes for observation.
Photo: Flickr

SS86H & SR93H
SS86H: L - 7.5m
SR93H: L - 20m
Forintos Gyula's first submarine, SS86H, was extensively demonstrated to the Hungarian military for river use in the early 1990s, particularly for mine clearance. That proposition is a serious one as the Danube has been mined repeatedly in WWI and WWII and unexploded mines remains a threat. The Hungarian Defense Forces did not purchase the sub.
The later SR93H is a highly stylized design with a military/sci fi theme but underneath is a true sub intended for a scientific polar expedition which sadly has yet to materialise. Despite its relatively great length, the pressure hull is very small diameter and the 5-6 man crew have to crawl and crouch at all time within the hull. Although it may not be the most practical or capable design, its mean looks deserve a film opportunity.

L - 20m
Built in the late 1980s in Holland by two guys who watched Das Boot and were inspired, this boat more recently suffers the indignity of being a houseboat. If anyone has more information, please comment to this article.

Saturday, July 3, 2010

Swedish Midget Subs

L - 11m, W - 1.4m, H - 1.7m
Displacement: 14 tons dived
Speed: 5kts dived
Crew: 6

Entering service in 1990, the Spiggen-II boat is among the most sophisticated midget submarines in military service. Primarily she is used as a training aid in ASW exercises, simulating an enemy submarine.
The internal arrangement has a large lock-out chamber amidships immediately below and inside the sail with the exit hatch on top of the sail. The boat is controlled from a two-crew 'cockpit' ahead of this, and the engine room to the stern. No torpedoes are carried but in wartime the craft could be used for sabotage or reconnaissance missions. Endurance is an impressive 14 days.

Sea Dagger
L - 16 - 20m depending on configuration
Kockums follow-on from the Spiggen, the Sea Dagger is a drawing board concept for a modular midget submarine series which, by 'swapping out' the core section, can be configured in various roles:
1) Attack sub armed with two lightweight torpedoes or mines
2) Swimmer delivery vehicle (Autonomous SDV)
3) Surveillance sub
4) Training (/target) sub
Although not unique for a midget submarine, the Sea Dagger is distinctive in appearance because it lacks the familiar sail.

DCE Torpedo SEAL
L - 2.5m (1 man), 3.4m (2 man)
Following the latest trend in wet subs ('chariots') the Swedish 'Torpedo SEAL' is designed to fit into a regular 533mm torpedo tube to allow easy deployment from minimally modified submarines. At least two chariots can be carried in a single torpedo tube. The system is still under testing. The two man version appears to be telescopic. Some versions have hinging doors which semi-enclose the crew, who crouch almost prone.
DCE have an excellent website:
Photos: DCE

SEAL Carrier
A sophisticated submersible boat, this design bears some resemblance to the SSK-96 Subscimmer. The craft is however significantly larger and high-tech. The main design, in service with the Attackdykarna (attack divers, SF equiv of SEALs/SBS) of Swedish military, is the SEAL SDV (Swimmer Delivery Vehicle) which can transport 6 combat frogmen. The crew of two sit in the forward position and have an airliner-style glass cockpit.

On the surface the craft can achieve 30kts. It takes on ballast in large tanks mounted in the forward section and deflates the skirt submerge. The craft can also run awash like semi-subs with just the top of the boat above water. In this configuration wake is very small. Large upward canted hydroplanes also mount small outboard electric motors.

Various minor variations/modifications have been seen with later versions featuring a small submarine style sail which houses GPS/sensor masts and a folding snorkel mast.

Other advertised versions are a remotely operated AUV (/ROV) carrier for mine warfare, and a fire support version with a remotely operated turret.

L - 10.2m, W - 2.1m
Speed: 30kt surfaced, 8kt awash and 5kt submerged
Underwater endurance: 2hrs
Combat radius - 370km
Photos: DCE

URF Rescue Submarine

This submarine is built by Kockums for the Swedish Navy. It is designed to rescue the crews of downed submarines up to depths of 460 meters. It is operated by three personnel and can rescue up to 35 submariners at one time. It is equipped with a four bladed shrouded propeller for forward movement at up to three knots and thrusters for station keeping and maneuvering, submerged endurance is 85 hours. It is operated from the Swedish Navy vessel HMS Belos. HMS Belos features a decompression chamber directly accessible from the URF when it is docked aboard. HMS Belos can also operate the British LR5 Rescue Sub. In addition to transport by sea it can be transported by road.

Photos: Kockums