The 100ft sonar?

The 100ft array on Matapan was a bottom bounce sonar. Horizontal beams are generally deflected upwards to the surface by the temperature profile of the sea, while below a critical depth, the beams are deflected downwards. That creates a shadow zone which cannot be reached, except by a bottom bounce beam.
I was the designer of much of the electronics for directional control/stabalisation. Together with the project leader, we took the first segment of the array with the associated electronics to Lake Pend Oreille (Idaho) for testing in 1973.

I guess this is topic is getting a little past it’s “sell-by ” date but if there is still any interest, I can add a few details. I worked at AUWE at the time and was one of the UK Team working on HMS Matapan.

It is fairly common knowledge that the Matapan system was designed primarily to investigate the use of bottom bounce propagation paths for long range surveillance. This requires a sonar with low(ish) frequency operation, good angular resolution (i.e. narrow beamwidths) and high transmit source level to work successfully, and hence the need for the large array.

As far as I am aware, little has been published in the open literature regarding the performance of the sonar but there are a few unclassified papers out there on the net outlining certain aspects of the system. I can pass on references if anyone is interested. Also, there are a few relevant photographs at http://www.curtistech.co.uk/sim/gallery/gallery.htm

I don’t think HMS Matapan was used for ST2031 trials. I believe the 2031I trials were mainly carried out on HMS Lowestoft, as were the early 2031Z trials, although trials on 2031Z was transferred to HMS Arethusa, when HMS Lowestoft was withdrawn from service.

Considering the flank sonar arrays on several modern sub designs, I suspect that your work is still relevant.

As a civilian scientist with the US Navy laboratory in San Diego, Calif. I was involved with the large sonar array installed onboard HMS Matapan. The studies were initially seperate efforts in the US and the UK. Sometime about mid ’60s it evolved into a joint effort when members from AUWE arrived in San Diego as exchange scientists.

Initially studies were directed at a conformal array installed following the ship’s structural shape. To this end a trials ship from the US was fitted with an array of flow flags co-located with noise monitoring hydrophones mounted below the water line. Trials were conducted to note flow lines while underway and correlate these with the noise patterns recorded on the hull.

In view of many unknowns, time and money constraints, and evolving ASW concepts in both US and UK it was determined that a one-off flat array approach would be attempted. Thereby, resolving the many issues of acoustics in the sea and if gains in detection could be realized from a large narrow beam sonar.

I served onboard HMS Matapan during the dockyard fitting, trials in Loch Fyne, and at sea trials. During this effort I made many friends in the dockyard, AUWE, and aboard Matapan, both officers and enlisted men. I will always remember their gracious outreach to a “yank” and thank them for all of the help.

I will be glad to answer questions regarding the sonar constrined to discussion of non-classified aspects only.

I served on HMS Matapan in 1976 spent all our time pinging a sub with a barrage balloon attached to it to confirm location.Not only did we have a 100ft transducer the draught was increased by 12ft and at the time the only ship in the Navy to have a bulbous bow .This created a bow wave that came up to the bridge wings at full power. The project itself was funded by the Americans and we had special accommodation built for the scientists on board.The power required to generate the pulse was created by a flywheel generator powered by 4 large diesel generators.We did at one point locate a sub more than 100 miles away which at the time was a record.

I dont have a picture of the Matapan but I do have one of her predecessor H.M.S. Verulam. She was attached to the 2nd frigate Squadron at Portland and conducted trials for sonar. This was damaged on one occasion when entering dry dock when they ‘forgot’ to retract the dome![ATTACH]169096[/ATTACH]

Thanks for the response Ollie, its stories like that one that remind us we are all human!

Sonar Trials Ship

I dont have a picture of the Matapan but I do have one of her predecessor H.M.S. Verulam. She was attached to the 2nd frigate Squadron at Portland and conducted trials for sonar. This was damaged on one occasion when entering dry dock when they ‘forgot’ to retract the dome![ATTACH]169096[/ATTACH]

Excellent reply, thank you very much Jonesey!

By integrated hull array I’m guessing you mean a wide aperture flank array as opposed to conventional bow and hull mount sets?.

The short answer is that its because surface vessels tend to operate at a fixed depth, i.e the surface, and therefore cannot take advantage of accoustic conditions in the varying layers in the water. This is where VDS and towed arrays come in. Why put the powerful sensor array on the hull of the ship, where it must stay limited in one accoustic regime, when you can trail the array between the layers for optimal accoustic performance.

The submarine is obviously not constrained in this fashion and can take its flank array deeper or shallower depending on local conditons.

Not much has been written about the work Matapan did in any great detail as far as I know. She did, ironically, participate in the trials of the 2031 towed sonar as well though – which was later to become the RN’s standard towed array.