My Beaut Aussie Cent

[Stephen White]

Next the operator's sight housing and sight unit (Tank, Periscope, No 15, Mk 1). The sight unit mounting is rotatable (although limited by stops to 65 deg) and has a limited range of elevation. The mounting is covered by a hinged sun/rain protective visor:







The seat for the mounting needed considerable enlarging and re-positioning. A new housing was made, together with a new sight housing. The sight itself is a Mike Stannard unit:











The protective visor and traverse limiter were soldered up from brass:









Regards

Stephen

[Stephen White]

Next up is what the Cent Illustrated Parts List calls the "Revolver Port":



It's a curious term, since I believe the only period when British tank crews were both issued with revolvers and ports from which to fire them was when the Mk IVs were in service in 1917/18. Indeed from WW2 onwards, the personal weapon for tank crews has been the 9mm Browning Automatic or a sub-machine gun of dubious utility.

Mike Cecil, as ever, has some answers. The term Revolver Port does indeed date from WW1, when crews were issued with at least one revolver for discouraging enemy infantry at close quarters, through various apertures. The Mk IV has storage specifically for a revolver close to the crew commander's station. The Mk IV has apertures with steel covers termed "revolver ports".

The WW2 British A22 Churchill has revolver ports in each side door and two in the turret. A parallel term, pistol port, carries across to US and Australian manuals for the M3 series Grant, reflecting the US use of the automatic pistol as the standard sidearm and the transition of in the British and Dominion forces from revolver to pistol. These WW2 ports were primarily viewing ports.

Mike then gets to Centurion:

When we come to Centurion, however, we seem to start seeing some conflict in the terminology. The User Handbook for Centurion Mks 1,2 and 3 published in June 1948, paragraph 39 defines the hatch as the 'Turret Port ... is provided in the left side of the turret. This port is intended for the
ejection of empty cartridge cases.' Exactly the same terminology and
definition is provided in paragraph 36 of the 1953 User Handbook for Tank, Medium Gun, Centurion Mk 3,5 and 6, and this definition remains unchanged during the life of the Centurion, despite numerous other amendments to the handbook.

However, the extremely detailed Technical Handbook for the Centurion Mks 1,2 & 3 first edition, published circa 1948, defines it as the 'Revolver Port'
which is carried forward to the publication of the Centurion Mk.5 Illustrated Spare Parts List in December 1958 which also defines it as the 'Revolver Port' (consisting of 12 individually numbered parts, including fastenings).

Some other publications have an each way bet: the British Electrical and Mechanical Engineering Regulation (EMER) G-102: Technical Description and its Australian equivalent, the Electrical and Mechanical Engineering Instruction (EMEI) M352: Technical Description, published in November 1958, has both terms - on diagrams, it is shown as the 'Turret Port' and in the text it is the 'Revolver Port'!


Whatever the terminology, it's clear the ports were not intended for conduction duals with unwanted visitors. Indeed, in Korea examples occur of one tank "dusting off" Chinese infantry trying to board another but no mention of gallant actions through the "revolver port", the use of which might have invited an incoming grenade or two.

Mike concludes:

The Centurion's Australian successor, the Leopard AS1, had a similar port in the left side of the turret, but being the Germans, the terminology and port's use were made quite clear in all the literature: it is the 'Ammunition Port' and it 'serves to pass gun ammunition and spent shells into and out of the fighting compartment' (Leopard AS1 MBT User Manual, first issue, page 19-25, paragraph 1.4.1.15).


So there you have it. Now to replicate the "Revolver cum ammunition port".

Stephen

[Stephen White]

The Cent's turret side armour is 112mm thick. The kit turret represents this perfectly. The kit revolver port flange however needs an insert on the inside to give it the full depth:





and some texture:



Next to turn a fully representative port cover and hinge:









and catch:



Comparison with the externally representative kit port cover:



Working operating lever. The handle pieces were turned on the lathe using a ball cutting attachment:





and the two roll pin retaining screws:



Complete and paint:







Real one:





Regards

Stephen

[Stephen White]

It's all too easy to forget the original vehicles have a real purpose, operational use, their heritage. Describing something as prosaic as a useless side hatch prompted some valuable insight into how the tank was fought. Overnight, two of my Australian correspondents have commented on ammunition re-supply in Vietnam. Both have reason to know, having been involved in some of the most intense fighting.

David Hay was the operator/loader on 064 at the Battle of Binh Ba in June 1969, when a couple of troops of Centurion and an understrength infantry company took on elements of an NVA regular regiment in prepared positions in a village.



David visits 064 in 2015:



David says:

I do recall we called the turret port the "pistol port" although I had absolutely no idea where this name came from. It always seemed one of the most useless design features of the Centurion and I don't recall it ever being used to pass ammunition (or pistols!) through. Most times when bombing up the ammunition would be stacked on the engine covers and passed down through the operators hatch. You are right in saying we didn't chuck out the cases and I seem to recall they were piled up in a heap near the refuelling point back at Nui Dat. What happened to them after that I don't know. When out working with infantry, it was unusual to fire more than a few HE or canister rounds at any one time so it was an easy matter to keep the cases somewhere on the tank. The one major exception was Binh Ba, where we went through almost the entire bomb load in a couple of hours. I recall simply tossing the empty cases up through the operators hatch as they piled up in the gun basket. I don't think I ever thought why it was we were keeping the cases but the idea of them not being used for IED's makes sense. (More often we would cut the bases off them to make ash trays!).

4 Tp, B Sqn carrying empty cases on the back decks:



Bruce Cameron commanded a troop in the last stages of Australian involvement in Vietnam. He describes attacking a heavily fortified communist bunker system in Long Khanh Province, similar to the one below, during Operation OVERLORD:



During our assault on Op Overlord, my three tanks fired 85 main armament rounds (and then had to resort to using hand grenades to 'clear' bunkers to save ammunition)..

Having 24 or more shell cases rattling around the turret is not best practice, especially with the likelihood of the traverse being jammed. Accordingly, cases were jettisoned from the turret whenever the opportunity arose. (We did have to pick them up later to prevent them being used by the enemy to make IEDs.)

I can't remember ammunition being loaded through the port. This was usually done by passing to someone on the engine decks who then passed inside through the operator's hatch.


In Feb 1970, 064 was also engaged in a similar assault (Operation HAMMERSLEY) in the Long Hai hills, known to the NVA/Viet Cong as the "Minh Dam Secret Zone", when a considerable number of main armament rounds were fired, clearing an extensive bunker system:



Thank you David and Bruce.

Stephen

[Christoffer Ahlfors]

Very interesting story!

[Stephen White]

Thanks Christian, it's always good to know someone has enjoyed reading this stuff.

Next, a minor but interesting component on the turret roof:



This is the header tank filler for the temperature-compensated link bar. What's that!? The link bar is a most vital component which physically connects the gun to the gunner's sight. It's description is here, explaining why it's in the turret roof (actually this is from Chieftain but the story is the same for Cent):





So although it's not high on the glamour stakes, this bit was very high on our list of servicing priorities. No juice in the tank, you lose the gun to sight relationship and the big bullets miss at long range. Not good.

Here is my version.



I've also started milling detail in the roof:



The circle is the welding reference for what had been the pressure relief valve armoured surround:



By the time 064's later turret was produced, this had been replaced by a blanking plate:



When the IR capability was added, this was in turn replaced by a conduit for the IR searchlight cable:



To follow.



Regards

Stephen

[Stephen White]

A combination of receiving some excellent reference photos and measurements from Paul Scott in Australia and getting some 5mm brass rod and tube started me on fabricating the IR Basket.

After successful trials in the early 1960s, the RAAC received authority to acquire from UK sufficient Infra Red kits to equip a squadron. The IR fit had been designed to counter the IR capability then being introduced on Soviet tanks. It consisted of a 1000 watt white light searchlight by Phillips USFA of Eindhoven, together with an IR filter, white light and IR headlights for the driver and IR sights for the driver, commander and gunner. A large basket was also introduced to stow the searchlight and provide general stowage.







ARN 169064 had a major base overhaul at Bandiana Base Workshops in late 1967 and the surviving AB417, the tank's record of service, shows the IR fit signed off on 1st Sept 1967:



To construct the end pieces, I decided to make a jig. Even with annealing, 5mm brass rod doesn't readily bend to an accurate radius, so I turned three templates and secured them to a steel plate:



The end plates were then relatively easy to form and solder up. The outer part was made from 5mm bar for stability and the centre struts from tube to allow the flattened, swaged ends to be represented.











Regards.

Stephen

[michael hilton]

Hello Stephen, like so many others, I follow your detailed modelling with great interest. I take my hat off to you.....Mick

[Russ Clark]

I really enjoy following this build also, people posting their builds keep me at my building best and I love to see the great craftsmen out there. lets all post some builds
Russ

[Michael Cecil]

Hi Stephen, Fantastic work as always. I marvel at your skills.

The page from 169064's AB417A 'Permanent Record Book for A Vehicles' (the 'log book') throws up some interesting aspects. These were modifications carried out as part of 064's second rebuild. While you would think that the last entry coded G107-195 about the installation of the IR would include what we call the 'IR Basket', it was actually supplied as part of the stowage modification kit and installed as part of the suite of stowage changes listed four entries above, under EMEI VEH M367-2. Interestingly, that entry also has a (later) red line through the gunners sight link and .50 RMG modifications, the reason being that those two modifications were not part of M367-2, but installed under other modification instructions which the workshop has not listed in the log book.

The above simply illustrates just some of the limitations of the vehicle log books for Australian Centurions - none are complete, many have entries that, when taken in isolation can be misleading (and are sometimes plain wrong), and none provide anything like a complete history of the vehicle. 064's log is a good example. The earliest entry is dated 1965, but the vehicle was delivered to 1st Central Ordnance Depot, Bandiana, in mid-1955, so the first 10 years - which included an extensive period of use in training, followed by its first complete re-build - simply cannot be learned from the AB417A. Neither can its end of life - there is nothing between 1972 and 1977 when it was being used for training at Puckapunyal. In short, there are no entries in the log book for about 3/5ths of 064's service history, and this is very typical of all the surviving Centurion AB417A log books for Australian tanks that I have studied.

Regards

Mike

[Stephen White]

In a recent post, I mentioned that 064 took part in Op HAMMERSLEY, one of the major battles involving Australian armour in Vietnam. A summary of HAMMERSLEY is here:

Operation Hammersley

Dates: 2FEB1970 - 9MAR1970

Area of Operations: Long Hai hills area, Long Tien District, Vung Tau Province

Allied Units: 8th Battalion, Royal Australian Regiment (8RAR)

Allied Casualties: 11 KIA, 59 WIA

Enemy Units: Viet Cong 445th Battalion

Enemy Casualties: 45 KIA (confirmed-but likely more), 1 POW

Objective: Reconnaissance

Significance/Notes: The operations of D445 (the VC battalion) in the area were seriously disrupted. Large enemy caches of food, equipment, and weapons/ammo were found and confiscated. 8RAR was awarded the Republic of Vietnam’s Meritorious Unit Commendation, including the Cross of Gallantry, for its actions during this operation.


064 took part as callsign 2A, the troop sergeant's tank of 2 Tp, A Sqn, 1st Armd Regt, commanded by SGT Leslie "Rip" Riley. Rip's is one of the crew signatures now gracing the transmission covers of the model.

The Long Hai hills, known to the Viet Cong as the Minh Dam Secret Zone, had been subjected to a number of operations designed to contain and ultimately eradicate this base area close to the port of Vung Tau, used by the Australians as their port of entry. This is an early use of Cents in the indirect fire role, in 1968:



By Feb 1970, contacts led to a major follow-up and clearance operation, HAMMERSLEY:



It was no easy engagement and the tanks were occupied both in close support of infantry and direct shock action against the main bunker complex.

There are relatively few photos but this one popped up out of no-where on Facebook the other day:



I've now confirmed that it is indeed 2 Tp, c/s 2, the troop leader Lt Jack Brennan's tank on the left and the troop corporal's tank on the right. The two figures in the centre are probably the squadron second in command, Captain Ben Bowd, and Jack Brennan. The troop appear to be in a relatively secure area and may well be observing the results of an air strike. I've asked Rip Riley if he recalls the moment. It's a pity 064 doesn't feature but it does open the possibility that this is one a series, which might include new photos of 064.

Thanks Mick, Christian, Russ and Mike for your comments, much appreciated.

Regards

Stephen.

[Stephen White]

Mike, thanks for the insight into the shortcomings of the AB417A as a record of service. Checking the 417s for my own tanks was both a chore and a task whose importance we often undervalued. But then what "Twenty something" likes the paperwork? That's my excuse.

On with the IR basket. My engineering attempts often provide a demonstration of chaos theory - a number of small errors don't always add up to the sum of the errors but magnify them several times over. I had thought the basket would be a relaxing run up to TankFest. The theory was, take the real measurements and angles, reduce to one sixth, draw a template and build. It turned out that I could either make the basket fit the tank or make it big enough to take the scale searchlight but not both:



I pored over the photo above, wondering why the real searchlight fitted but on my template it didn't. I'd forgotten this was a British designed tank. The designers had to create some extra space by displacing the partition to allow for the full width of the light. Not logical but it works. Had I spotted that to start with, I'd have saved a day of head scratching.

To minimise the chaos theory effect, I've now learned to spend a lot of time jigging components to hold them firmly and true. The soldering is then relatively straightforward:









Mostly complete and time for a trial fit:







Regards

Stephen

[martin pitcairn]

Really Nice work here, I love watching this build. Keep it up please.

Martin

[simon_manning]

nice work mr white, an impressive part now its together on the tank, gives it more delicate detail to the turret shape and adds interest once its packed with stowage, keep going looks superb, regards simon.

[Derek Attree]

Hi Stephen
This is a master class in fine modeling just love it .

Keep up the good work.

Regards.

Derek