Hein Mat seaplane recovery system

[Andy H]

Hi

Were all familiar with pictures showing seaplanes being recovered by their parent vessel, but so far I've only come across one picture of a Hein Mat being used (Pic below is from Catapult Aircraft by Leo Marriott).

The Hein Mat recovery system used a mat on a roller that was unrolled directly astern the recovery ship. It was tried by several European navies but was discarded by the beginning of WWII. This should not be confused with the U.S. Navy system in which the recovery ship steamed in an arc into the wind to create a slick for the floatplane to land. A bright yellow sled was let out on a cable off to one side of the ship. A barb-like hook on the bottom of the central float engaged a cargo net on top of the sled and then sled and attached plane were hauled in to the side of the ship where a crane lifted the aircraft back aboard. Although not without problems, this system was successful enough to be used from the 1920's until the end of the
floatplane era after WWII.

http://www.secretprojects.co.uk/forum/i ... 90.20;wap2

I know the Swedish Navy used Hein Mats on there Gotland Class cruisers but I'm unaware of any others! Also does anyone know why the RN decided against the Hein Mat system? Any info or specs welcomed.

Regards

Andy H

[Ironmachine]

Any info or specs welcomed.

Some info can be found in an article from the March 5, 1936 issue of Flight (it is available online) titled SPEEDING-UP the AIRCRAFT CARRIER. Revolutionary Thornycroft Design for High Speed and Manoeuvrability : Seaplanes Launched by Catapult and Retrieved on Hein Landing Apron:

The use of the Hein canvas allows the carrier to maintain speed throughout the picking-up operation, thus rendering it far less vulnerable to torpedo attack by submarine. Another advantage which perhaps is not at first so obvious is that, while resting on the canvas at the stern, an aircraft may readily be refuelled and provided with ammunition.
[…]
Turning to details of the principal features, there is considerable interest in the construction of the Hein landing canvas. The efficiency of the arrangement depends on the fact that the canvas acts in somewhat the same way as a hydroplane. There is thus much less resistance to towing than might appear probable.
The canvas, when not in use, is wound up on an apron winch drum in the stern of the aircraft carrier. When it is desired that an aeroplane should land on the canvas, the latter is paid out from the drum on to the sea over a platform provided in the stern. To facilitate this manoeuvre, two small sea-anchors are attached to the rear end of the canvas.
Details of the Canvas
The canvas is made of sailcloth and, so that it may be conveniently wound up on the drum, it has no longitudinal stiffening. In order to protect the canvas at the moment of landing, the lower part is provided with transverse boards of Oregon pine, and with mats. To smooth out the water and also the screw stream behind the canvas, and to prevent lateral lurching, the canvas is provided with a number of guide surfaces on the underside of its lower end. These surfaces consist of vertical or downwardly directed longitudinal fins of sail-cloth. The lower edges of the vertical fins are connected by a horizontal fin parallel with the canvas, so that longitudinal channels are formed through which water currents can pass.
The canvas terminates at its forward end in two ''tops” to which are connected main wire ropes that lead to the apron winch drum, and by means of which the apron can be paid out and afterwards drawn inboard. When the canvas is paid out and the tops come under water the whole canvas becomes submerged ready to receive the aircraft. Also connected to the tops of the canvas are auxiliary wire ropes that are led under two guide pulleys, journaled to opposite sides of the carrier, near to the sea level, and then led inboard. By drawing in the main wire ropes the canvas with an aeroplane thereon can be drawn near to the stern of the carrier, and by simultaneously drawing in the auxiliary wire ropes, the front end portion of the canvas will be kept low down so that the aeroplane will not slip backwards when near to the stern of the carrier. The inner ends of the auxiliary wire ropes are finally fixed to the carrier.

[Ironmachine]

I know the Swedish Navy used Hein Mats on there Gotland Class cruisers but I'm unaware of any others!

What follows comes from the article Search for a Flattop: the Italian Navy and the Aircraft Carrier 1907-2007 by Enrico Cernuschi and Vincent P. O'Hara, published in Warship 2007:

[The seaplane carrier Giuseppe Miraglia] was launched on 20 December 1923, but in December 1925, when almost complete, she capsized in a storm. Raised[...], Miraglia finally commissioned on 1 November 1927 and until 1934 performed a useful role in the battle fleet. Modified again with two large bulges which finally resolved her stability problems, the ship became too slow to operate with the Regia Marina's new fast battleships and, in spite of the introduction of the Hein landing mat, she spent the remainder of her long career as an auxiliary, being paid off in 1950.

[StefanSiverud]

I was able to find this Popular Science (May 1933, page 20) article by means of Google, complete with several photos showing the setup as used on SS Westfalen: http://books.google.se/books?id=8ScDAAA ... e&q&f=true
And another article from Popular Science (February 1933, page 13): http://books.google.se/books?id=pigDAAA ... ane&f=true
And one from Popular Mechanics (May 1933, page 662): http://books.google.se/books?id=J-IDAAA ... e&q&f=true

I'm sure there's more to be found looking in old magazines.

[Andy H]

Ironmachine & Stefan

What can I say but bravo for finding that information and pictures, very appreciative of your time/energy in finding it.

The one outstanding question is why the Royal Navy decided against it?

Regards

Andy H

[phylo_roadking]

Andy, I missed this thread earlier; on reading the Wiki entry for the Ark Royal/Pegasus, I came across THIS interesting sentence...

In 1930, Ark Royal was recommissioned again as a training ship and an aircraft catapult was installed on her forecastle, forward of her cranes. For the next nine years, the ship conducted trials and evaluations of catapults and seaplane launch and recovery equipment and techniques. On 21 December 1934, she was renamed HMS Pegasus to release her name for a new carrier that was then beginning construction. The ship was assigned to Home Fleet when World War II began and was mostly used to train seaplane pilots in catapult launching and shipboard recovery techniques, using the Fairey Seafox, Supermarine Walruses and Fairey Swordfish of 764 Squadron

There's a short bibliography on the Ark Royal/Pegasus entry...

Brown, David K. (1999). The Grand Fleet: Warship Design and Development 1906–1922. Annapolis, MD: Naval Institute Press. ISBN 1-55750-315-X.
Friedman, Norman (1988). British Carrier Aviation: The Evolution of the Ships and Their Aircraft. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-054-8.
Layman, R. D. (1989). Before the Aircraft Carrier: The Development of Aviation Vessels 1859–1922. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-210-9.
Layman, R. D. (1976). "HMS Ark Royal – Pegasus 1914–1950". Warship International (Toledo, Ohio: International Naval Research Organization) XIII (2): 90–114. ISSN 0043-0374.
Lenton, H. T. (1998). British & Empire Warships of the Second World War. Annapolis, Maryland: Naval Institute Press. ISBN 1-55750-048-7.
Poolman, Kenneth (1978). Focke-Wulf Condor: Scourge of the Atlantic. London: MacDonald and Jane's. ISBN 0-354-01164-2.
Sturtivant, Ray (1984). The Squadrons of the Fleet Air Arm. Tonbridge, UK: Air-Britain (Historians). ISBN 0-85130-120-7.

...one of which is specific to the Ark Royal/Pegasus and might provide the answer?

[Hoist40]

The French La Galissonnière cruiser class was designed to use a stern landing mat. The wide transom stern had a narrow slit across where the mat could be fed out and a crane at the stern to pick up the aircraft.

Don't know that they used it much but I remember seeing at least one photo of it being used


This photo shows the slit at the stern where the mat was fed out

http://hush.gooside.com/name/g/Ga/Galli ... ere_06.jpg

[Ironmachine]

A mat in use by Admiral Scheer en 1937:

Source: http://elhangardetj.blogspot.com.es/2010/12/el-cuarto-viaje-del-admiral-scheer.html

[glenn239]

In checking Wiki, that seaplanes weighed maybe 7,000lbs. Does anyone know how much weight the mat system (or a mat system) could carry?