The Chieftain's Hatch: Spring Grass

Canungra is barely a few miles in from the Gold Coast, doubtless Kokoda Barracks is a prime, highly desirable posting for members of the Australian Defense Forces. The chances are, though, that in late 1967, the tankers of the 1st Armored Regiment who were found there were more likely to be cursing the fact that they were there than they were appreciating its beauty and convenience.

This was the site of the Jungle Training Centre, and was a mandatory stopover for anyone in the Australian military about to go to Vietnam. They called it the “Battle Efficiency” course. There would have been three significant issues with it where the tankers were concerned.


Even today, Canungra is used for jungle training (ADF Photo)

Firstly, the fact that the BE course was really an infantry course. We tankers are not particularly enamored of the whole walking around, carrying things, and getting wet business. If we were, we’d have joined the infantry to begin with (If we had a choice). Secondly, the late 1960s was a period of National Service (i.e., conscription). Unlike, however, their expeditionary predecessors of the Australian Imperial Forces of WW1 and WW2, the conscripts did not get any say in the matter of going overseas to combat. They were volunteered, not volunteers. Somewhere over half of the Australian tankers in Vietnam were conscripted, and more than one were not particularly happy about it. Didn’t stop them doing their jobs, though. The third, and most important problem, though, was that they didn’t have much time to prepare to bring their tanks to Vietnam, and mucking about with a rifle in the rivers was not helping progress their task.

The tanks are, of course, the point of this article. As many of you have noticed, the Australian Centurion Mk 5/1 is in the game, and is being released. It seems to be the appropriate subject. Plus, of course, I’m a great fan of the lesser-known, and non-Antipodean folks may be unaware that Australia and New Zealand, in good ANZAC tradition, provided a combined force to fight in Vietnam. The in-game Centurion is modelled as the Vietnam service configuration, so let’s talk about it.

Spring Grass was the codename for the plan to move Centurions to Vietnam, and it was certainly sprung on the Centurion crews. The first that Armored Center or 1AR heard about the deployment was a broadcast on the news. The CO had to make a telephone call to find out if it was true. This, unfortunately, was something of the hallmark of the Centurion deployment. Everything was so secret that the people who really needed to know often were not informed.

While the unit set about trying to come up with a squadron to send overseas, there was a fortuitous rebuild going on for the tanks. This was actually part of a long-planned deployment of the vehicles (Code-name Mercurate), again, so secret that nobody in the Armored Corps knew what the upgrade was for. The Cents were nearly twenty years old that this point, and needed a bit of work.

Australian Centurions were delivered as either Mk 3 or Mk 5 tanks. The only significant difference was in the type of machine gun, Besa or Browning. In short order, the Mk 3s were converted. In the 1960s, however, a general improvement program was started. Some improvements, such as as the 100litre fuel tank on the rear (which necessitated longer tow cables), or the uparmoring on the front (To Mk 5/1 standard) were common to many Centurion operators. This included the addition of a large spotlight, infra-red capable, mounted on the mantlet, and stored in a rack on the bustle when not in use. The ranging machinegun, however, was not. Australia was the only nation to equip a .50 cal ranging machinegun whilst retaining the 20pr gun. Other modifications were brought about only after combat experience. The 105mm gun was not taken up given that the Australians did not perceive any great likelihood of encountering any tanks (i.e. T-55s) which would require it, and that the extra weight and expense was not worth it.

The Centurion Mk. 5/1 RAAC in World of Tanks. Use the code "CHIEFTAIN2019" when creating a new account for a great bonus!

The problem was that the vehicles were being modified at the Central Ordnance Depot in Bandiana, between Canberra and Melbourne. The tank crews, either at Puckapunyal or at Canungra, had never seen these new upgraded tanks. They had only a couple of months to get to understand the new gunnery systems, which explains the frustration they felt at having to waste a few weeks of training in order go to play jungle infantryman at the Battle Efficiency Course.  And, they only had a couple of upgraded tanks to do it. Most of the upgraded tanks went straight from Bandiana to Vietnam.

The haste was somewhat caused by the perceived need: ANZ forces had been operating in Vietnam for some time, with M113 APCs, and it was viewed that Vietnam was not suitable terrain for tanks to operate in. A number of engagements and losses with the APCs, however, determined that perhaps there was a need for the protected firepower of the tanks. Sooner rather than later.

It wasn’t just the equipment which was in need of training either. For efficiency reasons, Australian tank squadrons trained in troops of three tanks. On deployment, they would operate (or at least try to, pursuant to enough tanks actually working) in troops of four. They were able to cobble enough tanks together to actually do  four-tank training for the final exercise. For some of the training cycle, they even had to hand over the tanks to a CMF (Reservist) unit for a couple of weeks as they were doing their annual camp and needed the vehicles. Of course, doubtless this was not the same couple of weeks that they were in Canungra. (Later deployments would see the tankers at least go through Canungra as a unit, instead of just individual trainees dumped into a course as spaces allowed). The other minor detail was that Puckapunyal doesn’t really much resemble Vietnam, and there was a decided lack of infantry involved in the training for combat in an infantry-centric environment.

Puckapunyal. Some parts of Vietnam do look a bit like this. The Centurions didn’t often go there. (ADF)

Not that getting the tanks to Vietnam was particularly easy either. The first problem seems to have been that the logistics people presumed that the tanks would basically be going back and forth between Puckapunyal and Bandiana. However, the route to Vietnam did not pass through Bandiana, and the track from Pucka to Sydney Harbor didn’t even have a tank loading dock. Some improvisation was needed.

Things didn’t get much better in Sydney, when it was discovered that the crew of the chartered vessel, MV Jeparit, were on a bit of an anti-war kick, and refused to transport munitions and weapons to Vietnam. Royal Australian Navy personnel took the places of those who refused. The support vehicles, AVLBs and ARVs, were sent by Army-manned LSMs.

The first Cents arrived in Vietnam the end of February 1968, and were pretty quickly set to work. Equally quickly, some more modifications were identified.

Firstly, the side skirts and track guards had to go. The skirts kept trapping vegetation thick enough to grind the tank to a halt, and the track guards simply kept being pulled off. Eventually you will see photos of Centurions in Vietnam with track guards again, these are actually the side skirts which have been cut up and mounted: They figured that the armor plate the sideskirts were made of would do a better job of slicing through the undergrowth instead of being ripped off by it as the thin metal of the guards were doing.

The next problem was discovered in that the tanks couldn’t talk to the infantry. The radios were not compatible. This was solved, partially, by borrowing an AN/PRC-25 radio set in a rack behind the commander’s cupola on some tanks.

Problem number 3 came because of the heat and humidity. The rubber on the roadwheels simply was not holding up under the strain. Combine this with high attrition of the headlights, even with guards, from the jungle vegetation, and it became something of a no-brainer to simply remove (later reposition) the headlights and replace them with mounting points for spare roadwheels. Of course, being a new idea, it wasn’t a problem-free process. Adding the racks for the roadwheels  was painless enough, but once the wheels were mounted into position, it was discovered that the racks were so high that the roadwheel blocked the driver’s view, especially when buttoned up. The solution was to lower the rack in front of the driver, which is why on a lot of photos, you will see that the two wheels are mounted at different heights. Later conversions of vehicles in theater had both racks mounted lower.

The last notable change was to the smoke grenade launchers. They were removed as well, for two reasons. Firstly, nobody could see very far in the jungle anyway, so the utility seemed to be a bit limited. More importantly, though, they kept getting knocked about by the vegetation, and so there was little purpose in keeping them. As a result, it can be seen that our in-game vehicle is one of the earlier batch of vehicles, more or less mid-way through the first year of service.

Centurions only hung around in Vietnam for three years. As expected, mobility could be an issue, with occasionally tanks (and sometimes the entire troop) mired for days pending recovery.

Oftentimes troops would be parceled out, in a little self-sustaining organization complete with an ARV and bridgelayer. Ammunition expenditure was prodigious, with the primary round fired being Canister, which had a defoliage effect, making visible enemy bunkers which could then be engaged with APCBC or HE. Even the RMG became pressed into service as a coaxial. Oftentimes, entire bombloads would be used up requiring replenishment in the middle of a battle. Engagement was often incredibly close and vicious: A driver was credited with killing an enemy by use of his pistol. Sometimes it was the opposite, with shots on hillside caves in excess of 2km. The opposition could learn very quickly about showing light at night! A number of indirect fire missions were also conducted.

More typical terrain

Of course, infantry co-operation became absolutely critical in the close terrain, with both Australian and New Zealand infantry being supported, but the most important friends were probably the engineers and fitters (Mechanics). Centurion was vulnerable to most anything, one can imagine how, in close terrain, an RPG could be a threat. As a result, many Cents were holed. Even the Atomic Tank, if you go up and look at it as it is currently on display in Darwin, has a repaired RPG hole in the left hull. One RPG on another tank went through the mantlet, then an air gap, and then through the front of the turret behind the mantlet, going through some 10” of metal.

The big killer, though, was mines. The amount of suspension bogies and track links that the Australian tanks went through almost beggared belief. Initially, the mines exploded under the track, requiring repair in the field, the replacement suspension unit often being helicoptered in. 

Fortunately, the bogies are easy to replace (AWM Photo)

Later, though, mines were offset, to explode under the hull of the vehicle. And they were big enough to buckle and split the hulls: Casualties to drivers got to the point that in particularly suspicious areas, the Centurion would reverse into battle: Engines could be replaced more acceptably than the drivers. Crews and engineers became quite adept at spotting mines, but as they saying goes, they have to get lucky all the time, the opposition just needs to get lucky once. This was a problem never entirely solved, eventually the Aussies leased an M48A3 with roller from the Americans.

Yes, this one’s American, but it’s what it looked like…

That said, though, although the tanks may have been often knocked out, they were only rarely destroyed. When destroyed, they were still recovered. Many vehicles were sent home with split hulls, only to be refurbished. Examine particularly the underneath of surviving Australian Centurions, a good number are going to have welds where you wouldn’t expect them.

Personnel and vehicles did not rotate at the same speed. Personnel rotated after either a year in country, or if they were conscripts, when their term of conscription was up. Vehicles, though, we considered good for up to 4,000km before they were rotated home. Most all tanks would have gone through two or three engines, gearboxes, or final drives by the time they got to that point, though.

Rebuilt engines were coming in from the UK. Australia had to source a lot of spares to sent to Vietnam. (Photo link)

In the end, the Australian commitment scaled back, and with it, the tanks were withdrawn. For all the benefits they provided about firepower and protection, they were costing a whole hell of a lot of money and man-hours to keep in the field, and it was no longer practicable. The last tanks left Nui Dat in September of 1971.

Much was relearned from WW2 about the use of tanks in jungles, and the ability of tanks to go often where it was considered that they couldn’t. Much was also learned about the value of the tank’s firepower.  Over the years some 830 personnel cycled through Vietnam with 1 Armored Regiment. Of those, just over 70 were wounded, and six killed.

The time was up for Centurion, though, with its replacement by Leopard 1 coming only a few years later. Although I have no doubt that Leopard crews loved their mounts, I suspect that, especially in the minds of the Vietnam tankers, and the infantry they supported, the Leopard will never have quite the same place in the hearts and psyche as Centurion does.

This Digger is sitting on a Cent ARV.  (AWM)

Oh, and as a reminder, my Inside the Hatch video on Centurion was filmed on an Australian one in Cairns. Quite a number of Cents managed to avoid the scrapping torch and can still be seen at barracks and RSLs around Australia, in addition to a few runners in private hands and in musea. If there’s one near you, check it out, salute the old warhorse, and those who fought in her.

Bob, down under, will take you to the forum thread.