|
H.M.S. ULSTER -Bombed off Japan 1945
© Crown
Copyright/MoD (1945).
DAMAGE
REPAIRS TO H.M.S.ULSTER
On April
1st, 1945, while operating with a task force to the south of Japan,
H.M.S. Ulster was bombed by a Japanese aircraft. The bomb, which was
estimated to weigh between 250 and 500 lbs. fell only a few feet from
the vessel and the explosion blew a large jagged hole in the plating on
the starboard side, the centre of which was just forward of No. 54
bulkhead. At the time, the ship was steaming with both boilers connected
and the main throttles in use.
Within
three minutes of the explosion, the engine room and No. 2 boiler room
had flooded to within 3 ft. of the deckhead. As soon as it was possible
to enter the boiler room, examination showed that both main steam leads
on the starboard side were extensively damaged, that both superheated
and saturated exhaust ranges had collapsed, and that the main and
auxiliary feed discharge lines were wrecked. The considerable surge of
water which was entering and discharging from the ship's side rendered
further examination impossible and in any case it was considered
unnecessary.
Owing to
the extensive flooding, the vessel had increased her draught by 29 ft.
but remained upright. A considerable amount of top weight was
immediately jettisoned and she was taken in tow by H.M.N.Z.S. Gambia,
but was later turned over to a tug at the entrance to Leyte Gulf in the
Philippines.
While the
ship was under tow, steam was required at various times in order to work
the capstan. No. 1 boiler was pumped up on the first occasion using
water from the port fresh water tank and the 70-ton portable electric
pump. Subsequently, No,1 boiler was fed with an auxiliary feed pump
taking its suction from the main feed tank in the engine room. The total
time steaming in this condition was 18 plus hours. At first, the exhaust
steam escaped through the hole in the ship's side as the vessel rolled
and up through the air intakes to the boiler room as it was impossible,
owing to bad weather, to reach the atmospheric valves in No. 2 boiler
room. On the third day it was possible to open the atmospheric valves,
after which most of the exhaust troubles were over.
From the
beginning of the tow it had been appreciated that it would be
advantageous to trail the shafts and work went ahead to achieve this
end.
Unfortunately, the shafts were not fitted with special trailing collars
in the vicinity of the plummer blocks, so the thrust block covers were
removed and preparations made to break the couplings immediately forward
of the thrust blocks. All went well at first and the top three bolts of
each coupling were removed without any trouble, As both the main engine
turning gear bolts were in their stowage position below the throttles in
the engine room, efforts were made to retrieve them with the aid of
Salvus gear. This proved fruitless, however, as the surge of water was
too great and much floating debris was moving from side to side. This
fact was signalled to Gambia, who proceeded to manufacture a turning
bolt. When in receipt of this bolt the port engine was turned slightly
and immediately difficulties were encountered.
The
slight turning apparently disturbed the forced lubrication system,
resulting in a considerable volume of water rushing back into the gear
cases and drain tanks.
The tops
of the latter started to pant and were shored dawn, the head of water in
the engine room being approximately 8 ft. above the tank tops. The
thrust block covers were replaced quickly, but the water continued to
squirt out of all the gear case joints, sight flow indicators and drain
tank sounding tubes.
The
electric F.L. pump was started, taking suction from the drain tanks and
discharging via the starboard lubricating oil storage tank to the upper
deck. This relieved most of the pressure in the gear cases, but was
insufficient to empty them. For the remainder of the time afloat, these
tanks remained full of sea water. During the time the turning bolt was
being manufactured by Gambia, the strong-backs supplied for moving the
main gear wheel forward when the coupling was broken, were erected in
position. It was then discovered that only a slight pulling up of the
strong-back, the bracket for which is welded to the engine room
bulkhead, produced leakage in way of the welding and an effort to move
the gear forward would most certainly have torn the bulkhead. A
variation of strong-back was made in the ship.
On
arrival at Leyte, Ulster was placed alongside Tyne and No. 1 boiler was
thoroughly washed out and cleaned externally and internally. As was to
be expected, the interior of the boiler was very dirty, and the cleaning
operations took twice the normal time. The super heaters were opened,
when it was found that the salt deposit was very slight and only in the
vicinity of the Iower tubes of the downcomer headers.
Concurrently with boiler cleaning the boiler feed regulator and check
valves were stripped and cleaned, the steam line to and exhaust line
from the capstan engine were washed through with distilled water. The
shuttles of the boiler room oil fuel and auxiliary feed pumps were
removed and thoroughly washed, cleaned and oiled. All packing was
renewed. The water in the steam lines was introduced on the forecastle,
and each pump was washed through in turn. On completion of cleaning, the
boiler was pumped up to "WW," using distilled water to which had been
added 14 lb. U.S. boiler compound. Prior to docking, a conference was
held at which the U.S. Navy undertook to repair the shell plating and
No. 54 bulkhead. It was suggested by the U.S. authorities that the
machinery which had been contaminated by sea water immersion, be treated
as soon as possible with Tectyl. This is the trade name of a water
absorbing oil, which besides displacing the water, forms a protective
coating on metallic parts, It had frequently been used successfully in
the U.S. Navy and the suggestion to use it in this case was adopted.
After
docking, and as the water was running out of the engine room, fresh
water was sprayed over all machinery and 20 seamen followed on with rags
and dried out as much as possible. No. 2 boiler room was treated in a
similar manner, but in this case it was not so straightforward. The
extensive damage and general disorder was aggravated by lighting
difficulties, although much had been anticipated and a comprehensive run
of temporary leads was rigged.
At this
time, the labour situation was good, as, in addition to the ship's
staff, a boiler cleaning party and 2 E.R.A.s plus 6 E.R.M.s on loan from
Tyne were available. Owing to fleet requirements, however, 2 E.R.A.s.
and 4 E.R.M.s were withdrawn shortly after docking and from then onwards
all the work in the ship was carried out with the assistance of 4
E.R,M.s only, two joining from Resource.
As hands
were available from other departments, it was found possible to carry
out much of the work concurrently. Details are given under sub sequent
headings.
Main
turbine F.L. System
Salt
water was pumped out of the forced lubrication drain tanks and gear
cases by means of the electric F.L. pump, and drained out of the thrust
and adjusting blocks. The; main oil cooler drain plugs were removed and
coolers were found to be full of good oil. All the strainers and pump
were cleaned out. The F.L. drain tanks were washed out with fresh water
and wiped out. They were then refilled with fresh water, which was
pumped round the system (coolers being by-passed) for six hours, the
engines being moved slowly by hand at intervals. There was a
considerable delay at this stage as it had been intended to run the main
F.L. pumps on air, but this proved impossible and the 70-ton portable
electric pump was rigged up to take its suction from the drain tank
manhole, discharging via an adaptor fixed on top of the F.L. strainer
by-pass cock. The fresh water was then pumped out of the F.L. tanks and
drained from the thrust and adjusting blocks. The drain tanks were then
cleaned.
About 150
gallons of Tectyl was run into each drain tank and pumped round the
bearings for 11 hours, the engines being turned at intervals. Tectyl
appears to be a type of paraffin, but is much more oily to the touch. lt
has the property of adhering to steel in place of water and is stated to
be soluble in lubricating oil.
Tectyl
was then pumped back into the storage tank and an attempt made to
renovate it by means of the oil separator. This failed, however, so the
Tectyl was returned to the U.S. authorities in an emulsified state. The
drain tanks and thrust and adjusting blocks were then thoroughly cleaned
out.
The main
gearing was opened up and cleaned, together with all bearings and sumps.
After thorough cleaning, the drain tanks were filled with S.M.L.O. which
was pumped round the system for three days. At the end of this time it
was badly emulsified and a considerable amount of Tectyl was floating on
top. The drain tanks were again emptied, thrust and adjusting blocks
drained and gauzes removed. The drain tanks and F.L. strainers were
carefully cleaned and the system refilled with clean S.M.L.O.
Interior of main turbines.
All the
salt water was drained out and the condensers and L.P. turbines washed
through with fresh water. The condensers were filled with fresh water to
the underside of the turbine shafts which were turned to wash the
blading, the turning being arranged to coincide with the movement of
engines previously mentioned. Water was then drained off to about 6 in.
above the top of the condenser tubes. Carbon packing was then removed
from the turbine glands.
Spraying
of the turbine blading with Tectyl was then carried out through all
available orifices, using Nuswift fire extinguishers which were found to
give a far more penetrating spray than the nozzles supplied with the
Tectyl. The turbine access doors were then replaced and the spraying
process repeated several times. It was found that an oily atmosphere was
produced inside the turbines which it was hoped would penetrate to the
fixed blades in the top casings.
All the
Tectyl was then pumped off the top of the water in the condensers to
prevent its access to the feed system. The condensers were then emptied,
washed through and the sumps cleaned.
Turbo
auxiliaries
Stop
valves and exhaust valves were removed, F.L. systems drained out and the
cooler tube stack removed. All exhaust lines were washed out with fresh
water through the valve cover on the feed heater and also from the
capstan.
The
turbine casings and F.L. systems were washed through with fresh water.
Turbine covers of the extraction pumps, turbo-generators, distiller pump
and circulators were removed and all parts washed through, cleaned and
checked. The main feed pump turbines were filled with Tectyl and turned.
All carbon glands were removed, journals cleaned and carbon packing
adjusted. Governors and trip gear were then cleaned and refitted.
Reciprocating auxiliaries.
All steam
and exhaust valve covers were removed and the cylinders washed out with
fresh water. Packing was then removed, shuttles refitted and the
cylinders sprayed with Tectyl. The pumps were then closed up, glands
repacked and the turning gear positioned.
In
dealing with the pump ends of reciprocating pumps, the glands were
unpacked and the barrel washed out with fresh water. If the barrel was
of ferrous metal, Tectyl was also applied.
Miscellaneous items.
Owing to
the flooding of the engine room, practically everything had been damaged
by salt water. This necessitated the careful checking of pressure gauges
and instruments of all kinds. These were removed, examined and rinsed in
fresh water, being afterwards tested and adjusted by the repair ship.
Motor
armatures, starters and other electrical fittings were washed through in
fresh water and sent to H.M.S. Artifex for baking and refitting.
The feed
tanks were washed out with fresh water and thoroughly cleaned out. They
were then refilled with fresh water and boiler compound in the
proportion of 2 lb. per ton added.
In order
to ensure that no damage had been overlooked, careful checking of the
main turbines and turbo-auxiliaries was carried out. This included
finger plate readings, blade tip clearances and so on.
Machinery repair.
The work
included the following items:-
(a)
Starboard main steam pipe, after length, from No. 1 boiler replaced by
plain pipe 5 in. diameter.
(b) Turbo
and saturated exhaust pipes in way of damage renewed.
(c) Feed
heater drain pipe renewed.
(d)
Superheater drain pipes in way of damage renewed. [e) Starboard main
steam Iead to No. 2 boiler blanked.
(f)
Auxiliary feed discharge to heater, and main feed discharge to No. 1
boiler, pipes and fittings in way of damage renewed.
(g) Main
feed discharge to No. 2 boiler blanked.
(h) Steam
and exhaust leads to auxiliaries in No. 2 B.R. blanked.
(j) No. 2
starboard fan removed complete.
(k)
Auxiliary circulator removed and pipes blanked.
(I)
Temporary lead from saturated steam range to No. 2 B.R. bilge ejectors
rigged.
(m)
Starboard telemotor leads renewed in way of damage,
(n) Port
T/G armature baked and made fit for use (half load).
Lagging.
Very
little of the lagging which had been under water remained when the ship
docked, and its replacement was one of the most difficult problems
encountered.
A small
supply was flown up from Sydney, but this was hopelessly inadequate and
it was necessary to "scrounge" from other ships. Much of the lagging
from No. 2 boiler room which was no longer necessary was utilised, and a
large supply of millboard was obtained from H. M.S. Illustrious,
together with two rolls of asbestos cloth. Luckily one of the stokers
had some experience of lagging and he, together with eight seamen,
formed the lagging team.
All pipes
were covered with a thick layer of millboard and then bound and sewn
with asbestos cloth. Machines such as the main circulator and extractor
pumps were packed around the rotor casings with millboard and asbestos
cloth jackets made to fit.
When
warming through for the first time, the effect of the drying lagging was
most unpleasant. The engine room became very hot due to being full of
steam, and the smell was most objectionable.
Throughout the remainder of the time when under main steam the engine
room temperature was always 8" F. above the normal for the engine room.
The
"hot-spots " were in the immediate vicinity of the H.P. turbines where
the lagging of the rotor casings had been considerably impaired by the
action of the sea water. No excessive bearing temperatures were
experienced but all were taken at half-hourly intervals whenever steam
was on the main engines.
The
aforementioned work was carried out by the ship's staff of H.M.S.
Ulster, and comprised engine room ratings, torpedo men and seamen,
assisted by working parries from H.M.S. Tyne. The pipe work was carried
out by H.M.S. Resource. The ship docked in the U.S. dock at Leyte on
April 10th, undocked on April 19th and carried out sea trials on May
10th.
Trials.
During the basin trial the whole feed system became badly contaminated
and No.1 boiler salinity rose to about 50 grains per gallon. After the
trial, the feed tanks were pumped out, cleaned and refilled with
distilled water, and the extraction pumps discharged to bilge until
clear. No.1 boiler was then shut down, opened out and washed through.
During
the sea trials, slight contamination showed, but this cleared eventually
and impurities began to concentrate in the boiler. After the sea trials
the boiler was again washed through and refilled with distilled water
and U.S. boiler compound.
By the
end of the sea trials, the main turbine oil was getting very thick, so
the oil system was cleaned out and replenished on return to harbour.
There was little water in the oil, and it is thought that the Tectyl was
probably responsible for the emulsification occurring. Typical bearings
and adjusting blocks were examined and found to be in satisfactory
condition. Trials were carried out in stages ending up with half an hour
at 21 knots, an astern trial at 100 r.p.m. and steering trials.
Leyte
to Sydney.
The
voyage was completed non-stop, oiling from H.M.S. Striker being carried
out en route. This operation, by buoyant hose method, presented rather
more difficulty than usual. Both Chadburns turbometers had been
condemned by Tyne and neither worked. In addition, one of the H.P. ahead
receiver pressure gauges faiIed. By having an E.R.A. on each throttle
backed up by two leading stokers, detailed to count the revolutions of
each engine, the station keeping improved considerably. On one occasion,
however, Ulster moved close up, under the counter of the oiling ship and
the telegraphs altered to slow astern. No difficulties occurred in
executing this order, but a little later, when ordered to stop, it was
found impossible to close the starboard astern throttle.
As only
50% of the astern nozzles are controlled by nozzle valves, a
considerable amount of ahead steam was required until the oil hose was
disconnected shortly afterwards.
The
astern manoeuvring valve was eventually closed by using a large spanner
on the square formed on the end of the valve spindle. Subsequent
examination at Sydney showed that the ball thrust on the valve spindle
had been considerably attacked by salt water and had seized up.
Later on
in the day of oiling, the weather deteriorated and the pitching of the
ship caused an excessive axial movement of the armature and main gear
wheel of the port T/G. The forward diesel generator was started, the
ship's electrical load transferred and the T/G stopped. The gear case
was opened up and it was discovered that the roller and ball thrusts on
the main gear wheel journals were loose. Again, salt water was put down
as the cause of the failure.
The
gearing and associated ball and roller races of the starboard T/G were
examined, and found to be in perfect condition, so the gearing was
changed over complete from the starboard to the port machine. The
coupIing bolts of the armature presented no difficulty but, when
tightened up the effort to turn the rotating parts was considerably
greater than before and it was decided not to run the machine in this
condition.
The
remaining five days of the trip were made with the diesel generators
taking the ship's load.
At
Sydney, the gear wheel journal was built up by nickel spraying and then
ground to fit the spare ball and roller races. No subsequent trouble has
been experienced with this machine.
The main
engine lubricating oil became very thick and discoloured and very little
success attended efforts to separate the impurities. The emulsifying
effect of Tectyl was again noted, and its rather distinctive odour could
still be detected in the oil on arrival at Sydney. A sample of the oil
taken at this time was allowed to stand for four days. At the end of
this period a layer of Tectyl about 1/16 in. thick had separated out and
floated on the top of the S.M.L.O. The entire lubricating system was
thoroughly cleaned, a considerable quantity of sludge being found at the
bottom of the drain tanks. The system was then refilled with new S.M.L.O.
The
chloride content of the boiler water had risen from 2 to 15 grains per
gallon after one week's steaming, but remained constant at that figure.
At Sydney the boiler was cleaned externally and internally, and on
arrival in U.K. the chloride content of the water was five grains per
gallon.
At
Sydney, Ulster had no priority with regard to repairs, again due to
heavy Fleet requirements in this direction. The ER. department had some
slight assistance during the boiler cleaning period, but the
considerable amount of stripping and refitting of machinery was wholly
undertaken by ship's staff.
An
alternative electrical supply for the engine room fans was run from the
for'd switchboard, and this too was accomplished by the ship's staff.
From
Sydney to Pearl Harbour the performance of the machinery was fairly
satisfactory. The new boiler gauge glasses proved to be of a most
inferior quality and the average daily consumption was three. The
lubricating oil, despite great efforts at separation, steadily
deteriorated. Because of this, the starboard lubricating oil storage
tank was pumped up with oil from the system and allowed to settle for
two days. After this period, the good oil which had separated out was
siphoned down to the drain tanks and the storage tanks cleaned out. This
practice was a regular routine throughout the remainder of the trip. At
Pearl Harbour the lubricating oil system was once again thoroughly
cleaned. New boiler gauge glasses manufactured by Pyrex were obtained,
and there were no subsequent failures.
Thirty-six hours after departure-from Pearl Harbour an unusual " roaring
noise " was reported in the furnace of No. 1 boiler. Although there was
no distortion of the flame in the furnace, coupled with the fact that
the funnel exhibited no white smoke, it was assumed that a Superheater
element was defective, and a careful check of the consumption of feed
water was made.
During
the following 24 hours the consumption jumped from 9 to 25 tons, and the
assumption was proved correct. The evaporator, however, was maintaining
its output, and despite the extraordinary expenditure of feed water it
was found unnecessary to ration water from the ship's tanks.
At San
Diego the defective element was Iocated and removed, pugs being inserted
in the headers. The boiler was tested by water pressure to 300 lbs. per
sq. in., and found to be satisfactory, The U.S. Navy yard at San Diego
wiIIingly undertook any machine work, but the removal of the element was
carried out by ship's staff.
Shortly
after leaving Panama, the neck of the top disc of the lubricating oil
separator fractured, and from then on the machine was not run.
At
Bermuda, all the dirty Lubricating oil was landed and after a thorough
cleaning of the F.L. system it was filled with new S.M.L.O. On arrival
in the United Kingdom this oil was fairly dirty but exhibited no signs
of emulsification and no trace of the Tectyl remained.
Two days
prior to the ship leaving Sydney all the engine room department with the
exception of the C.E.R.A., chief stoker and seven stokers were drafted,
their reliefs coming from other ships which had been on the station a
long time.
Although
the majority of the new arrivals were from destroyers, it was some
little time before they were conversant with the rather peculiar
conditions in Ulster, and this proved to be a severe handicap at first.
Other
troubles were those associated with pressure gauges and engine-room
lighting. Many of the former either registered inaccurately or shed all
the paint off their faces, necessitating marking lines on them with
scribers or paint. Despite great effort by the torpedo branch, it was
quite impossible to wash through the engine room bilges without putting
many of the lights out and this practice was discontinued. Pumping out
the bilges too was a problem, as much of the lagging which had washed
off the pipes still remained and continually choked up the suction
strainers.
|
Site Directory |
