The Collins Class Submarine Story
Page 26
oratory, where microscopic examination revealed that their chem-
ical composition was too lean in the critical alloying elements.
Discussions with the Swedish steelmaker SSAB revealed that they
had four experimental samples of an enhanced high-strength low-
alloy steel that might do the job, and four plates were promptly dis-
patched to Australia. At the Cooma quarry three plates performed
poorly, but the fourth was brilliant. Examination back at John
Williams’ laboratory showed that the failed plates had too great
a concentration of the four alloys in their composition, creating
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Explosion bulge testing
clouds of tiny clusters dispersed throughout the metal that could
reduce cracking resistance under impact.
The fourth sample provided the correct chemistry. Further
laboratory testing allowed BHP to refine the alloy composition,
and Bisalloy to standardise production processes. The product’s
quality now could be verified by manufacturer and users. The
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Explosion bulge testing ( cont.)
result easily passed the explosion bulge test. In submarine con-
struction, its consistent quality and ease of welding in comparison
with the HY series was critical for the successful construction of
Collins class hulls.
Ritter and his colleagues also worked to establish the welding
technology – the metallurgy, the qualifying and testing regime,
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Explosion bulge testing ( cont.)
1 The first Project Director, Captain Graham White. (Photograph courtesy of
Graham White.)
2 ASC negotiation team of the day, Canberra, January 1987. Front row from right: Roger Sprimont, Bo Bennell, Pelle Stenberg, Olle Holmdahl. Gunnar Ohland third from the left. (Photograph courtesy of Pelle Stenberg.)
3 Contract signature day for the Collins project: (l-r) Rear Admiral Oscar Hughes, Geoff Davis, Fred Bennett, Kim Beazley, Roger Sprimont. (Photograph courtesy of RAN.)
4 Singer Librascope staff, including Bill Hudson (centre) and Arnold Peters
(second right), with Oscar Hughes (second left) and Rick Neilson (right) at Singer Librascope in Glendale, California. (Photograph courtesy of Defence Materiel
Organisation archives)
5 From left: Pär Bunke, Ian Nicholson (Australian Ambassador to Sweden), Paul P˚alsson, Rick Canham and Kurt Jönsson (Kockums’ construction and outfitting
manager) in front of a Västergötland class submarine at Kockums’ yards in Malmö.
(Photograph courtesy of Defence Materiel Organisation archives)
6 Stiffening frames being lowered into a hull can before welding. (Photograph courtesy of ASC Pty Ltd.)
7 Hull section or ‘can’ being welded. ASC welders achieved world-class results, with a remarkably low number of faults and very accurate circularity, a critical factor in hull strength. (Photograph courtesy of ASC Pty Ltd.)
8 Central section of submarine under construction at ASC. Control room viewed from aft. (Photograph courtesy of ASC Pty Ltd.)
9 Equipment platform being inserted into the control room section. All major
pieces of equipment and wiring have been already been installed. (Photograph
courtesy of ASC Pty Ltd.)
10 Submarine under construction at ASC, with hatch in the bow over cylindrical array removed for access. (Photograph courtesy of ASC Pty Ltd.)
11 The engine room team of marine technicians and engineering officer from
HMAS Collins at the start of sea trials, 31 October 1994. Front l-r: Anthony ‘Dog’
Masters, Paul ‘Bulkhead’ Newman, Troy Battishall; 2nd Row l-r: CPO Phil Ivins (DMEO), Mark ‘Artie’ Beetson, Jim Taaffe, Marcos Alfonso (MEO), George ‘Eugene’
Lakey, Lindsay Hinch, Sammy Brennan, Gary ‘Chook’ Fowler; Back right-hand side: Andrew ‘Birdman’ Ravenscroft. (Photograph courtesy of Marcos Alfonso.)
12 L-r: Hans Ohff, Rear Admiral Peter Purcell, Captain Paul Greenfield, Olle
Holmdahl, Commodore Geoff Rose, Captain Kit Carson, Commander Peter Sinclair.
(Photograph courtesy of Peter Sinclair.)
13 Kim Beazley and Commander Peter Sinclair at HMAS Collins periscope. (Photograph courtesy of Peter Sinclair.)
14 Rear Admiral Peter Briggs and Commander Peter Sinclair. (Photograph
courtesy of Peter Sinclair.)
15 General John Baker, Chief of Defence Force, standing left, and Ian McLachlan, Minister for Defence, right, at sea on a Collins, looking over the shoulder of a combat system operator. (Photograph courtesy of RAN.)
16 Farncomb at sea, 1997. Far left: Bronwyn Bishop, Minister for Defence Support; second right: Hans Ohff. (Photograph courtesy of RAN.)
17 A Mark 48 torpedo fired from over the horizon by HMAS Farncomb hits the ex-HMAS Torrens off the WA coast 14 June 1999. (Photograph courtesy of RAN.)
18 HMAS Farncomb arrives at Fleet Base West from an operational deployment with a broom and Jolly Roger flying – traditional symbols of success. (Photograph courtesy of RAN.)
19 A Leading Seaman Marine Technician checks one of the Hedemora diesel
engines. (Photograph courtesy RAN.)
20 RAN acoustic warfare analysts undergoing training in a shore simulator at Fleet Base West. (Photograph courtesy RAN.)
21 A combat system operator at work on a Collins class Submarine. (Photograph courtesy RAN.)
22 HMAS Sheean undertakes a helicopter transfer with an RAN Seahawk aircraft.
(Photograph courtesy RAN.)
23 HMAS Sheean sails from Fleet Base West, radar mast raised. (Photograph courtesy RAN.)
24 HMAS Collins with communications, periscope and snort induction masts raised. (Photograph courtesy RAN.)
25 HMAS Rankin embarks a practice Mk 48 torpedo at Fleet Base West.
(Photograph courtesy RAN.)
26 HMAS Waller prepares for a helicopter transfer. (Photograph courtesy RAN.)
27 Submarine Escape and Rescue Centre at Fleet Base West, Commodore Rick
Shalders explains escape training to the Chief of the Malaysian Navy. Building in Australia also meant building training infrastructure. (Photograph courtesy RAN.) 28 Commander Andy Keogh, the Commanding Officer of HMAS Sheean, and
Governor-General Major General Michael Jeffery AC CVO MC with the Gloucester
cup for 2005, awarded to the best ship in the RAN. (Photograph courtesy RAN.)
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Explosion bulge testing ( cont.)
and the guidance that would overlay the welding processes and
equipment chosen by Kockums for the exacting task of submarine
building. The key processes were manual metal arc (conventional
stick welding) and the automated process of submerged arc weld-
ing, in which a machine feeds welding wire and pours a layer of
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granulated flux that ‘submerges’ the intense arc glare to protect
the molten metal from atmospheric contamination. The guiding
principle was that the welding must remain practical in an indus-
trial environment.
An unexpected bonus of researching a novel alloy was that
companies from around the world were willing to provide the
latest equipment and consumables – stick electrodes and welding
wires plus granular flux – for trials on the Australia
n steel. As
Ritter observed, his research gave them ‘a “free” test house of
the highest international reputation, for their latest experimental
products’. Working with the ASC welding engineer, John Taylor,
the DSTO evaluation team found that only one source in America
provided suitable electrodes, one factory the granulated flux, and
one brand the wire that met the project’s requirements.
Ritter’s team also contributed to the development of the weld-
ing metallurgy by overturning an internationally accepted norm.
Conventionally, the deposited weld metal in the joint was of a
greater strength than that of the surrounding plate because it
seemed to make for a safer construction. Work following this
approach was nearly always destroyed by Ritter’s bulge tests. Bet-
ter results were obtained by having the weld metal of compara-
tively lesser strength. Furthermore, in Bob Phillips’ work on hull
penetrations, the lower strength (HY80) forged steel welded to
hull steel only ever passed the bulge test with lesser strength welds.
With a few days to spare before the deadline for pre-tender
development expired, DSTO had provided the project with a high-
performance, locally-produced steel, verified those off-the-shelf
welding products that would meet the construction requirements
and provided welding procedures for ASC to use in the construc-
tion of the submarine. Ritter’s team went on to extend the range
of materials and welding techniques and products certified for use
on the submarine. A regime for qualifying as safe every item in
the submarines’ pressure hulls was established.
With the product proven, DSTO could now develop criteria for
managing materials during the submarine production cycle. The
understanding built on the original work had to be transferred to
the everyday tasks of steelmaking, materials acceptance, welding
procedure qualification and non-destructive inspection.
Steel mills and submarine builders seldom set about blowing
up samples of their output. The data from the explosion bulge
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tests had to be reformulated in a way that could be transferred to
contractual specifications for steel and welding and could be vali-
dated by accepted industrial tests, namely the tensile and Charpy
impact tests. Neither much resembles an explosion bulge test. The
Charpy test, for instance, uses small, notched test pieces one-fifth
of the thickness of the bulge test plate and subjects them to an
impact of only one-thousandth of the explosion.
For ‘shop floor’ testing, Ritter’s team had to develop criteria
that matched the performance they had observed against explo-
sives. They ran a parallel series of laboratory testing including
dynamic teardrop-weight and fracture toughness tests to provide
an independent scientific validation, and Ritter synthesised all the
test information into what he called ‘mechanical property maps’
that allowed a reliable interpretation of the industrial level tests.
It was reassuring that DSTO’s work indicated that quality con-
trol of work with high-strength low-alloy steel largely fell within
recognised industry norms.
The same process of industrial standardisation had to be
achieved for the welding. At the time Ritter was well aware that
the inability to control transverse cracking had led to the rejec-
tion of two-thirds of the initial welds on the USS Seawolf. Yet with
Bisalloy’s novel high-strength low-alloy steel there was a greater
risk of transverse cracking in the weld metal than in conventional
materials and the problem was little understood. The DSTO team
was again breaking new ground.
Brian Dixon compiled a ‘welding acceptability map’ similar
to the steel testing guide, and it was found that the technique
of using a large number of small ‘stringer bead’ runs of weld-
ing material could produce a join of adequate toughness. Given
the thickness of the submarine plate the technique required up
to 50 runs. Nonetheless, the final beads on the surface provided
inherently brittle zones under explosive loading. Dixon devised a
procedure for capping the surface of the weld joint that became
known as a ‘top-hat’ weld profile. Even under severe explosion,
such specimens suffered only limited surface cracking along the
weld edges, rather than complete fracture.
With the development of tested procedures and an empha-
sis on high-quality workmanship, Ritter’s team gave Australian
industry usable and economic access to advanced materials tech-
nology. Using automated ultrasonic testing technology sourced
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from the Forces Institute of Denmark, and in cooperation with
ASC and Kockums, the DSTO team developed methods of non-
destructive weld inspection. There was a substantial change-over
from radiographic to ultrasonic weld inspection that led the way in
Australian industrial practice. Throughout the submarine building
program at ASC, the number of faulty welds needing to be redone
was around one tenth of the average in world submarine construc-
tion. Over time, methods of ultrasonic inspection were improved
and when earlier work was checked, no undetected cracking was
found.
During 1986 DSTO became involved in assessing the equip-
ment required for the new submarines. The Oberons’ upgrade
provided experience of modern configurations for passive sonar
receivers but the performance and potential of these new sensors
was still not clear. David Wyllie was involved, along with many
others, in studying the options for the new submarine’s sonar sys-
tem, a process that helped shape the sonar and combat systems.
Flank array sonar provides data in the low-frequency
spectrum for detection and other functions and is designed as
a long-range noise sensor. Distributed array sonar operates in a
higher frequency range and does a similar job to the flank array
but also provides range and bearing at torpedo range. The cylin-
drical array sitting in the bow works at frequencies that overlap
the others but goes to the higher spectrum to achieve fire control
solutions and provide weapon guidance. Experiments using towed
arrays for passive long-range detections were also conducted from
the Oberons.
The RAN laboratories tested the performance of the flank array
sonar on the upgraded Oberons and found that it was only at its
most effective for the short time that the submarine could maintain
itself in an ultra-quiet state, but significant improvements could be
achieved with the use of advanced signal processing techniques.
DSTO sought to find out how the newer systems proposed for the
next submarine would behave, but it remained concerned about
the performance of flank array systems. In contrast, the Oberons’
distributed array appeared to work well re
gardless of how the
boat was operating.
The DSTO study suggested maximising this potential by dis-
pensing with the flank array, adding a towed array sonar, minimis-
ing the size of the cylindrical array and transferring the weight
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savings to a more powerful distributed array system. In overall
performance, throughout the arc of coverage and over impor-
tant frequencies, this would give the new submarine a better
performance than that achieved by the Oberons. Although it was
unwilling to give up the flank array as a back-up, the navy sup-
ported DSTO’s conclusions and the senior navy command was
anxious to have these requirements included in the negotiations
for the contract.3
Optimising the performance of the distributed array would
mean lengthening the after casing and raising its sides closer to
the perpendicular, although it was recognised that this would have
effects on the pattern of water flow around the hull. In any event,
the after casing would need to be raised to accommodate the drum
and winch for the towed array. The DSTO study promised to
provide the new submarine with improvements in the ability to
handle and analyse acoustic data but also set in train processes
that would lead to one of the most serious problems that was to
face the Collins class – unexpected and excessive hydrodynamic
noise.
A chemistry PhD working at Maribyrnong, David Oldfield had
developed barnacle-repellent rubbers and solved major difficulties
with the Mulloka sonar system before the navy approached him
in 1980 to ask what he knew about anechoic tiles.4
At that time the practice of covering submarines with rub-
berised tiles was one of the most closely guarded secrets of the US