NMD 11 3/25/1/G
NORTHERN MILITARY DISTRICT,
P.O. BOX 2178,
25 Mar 52
9 COAST REGT
CENTURION TANKS IN KOREA - REPORT BY LT J BROWN RNZAC.
1. Enclosed is one copy of a report by Lt. J Brown, RNZAC, on Centurion tanks in KOREA.
2. At the time this report was written, Lt Brown with the 8th Hussars.
Chief of Staff
NORTHERN MILITARY DISTRICT
The subject lends itself to division into two parts. Part one - the performance of the single tank; Part two – Tk. tacs. The first Part I shall again sub-divide into the three old whipping blocks Speed, Armour and Armament. The second Part I shall also divide into three - Swans - Set-piece Attacks, and Def.
Perhaps a fairer title would be "Mobility and how to maintain it" since the CENTURION will only do 25 mph down hill and with a tail wind. But it will maintain a steady 20 mph on reasonable going, so-long as the petrol lasts, and in KOREA that is plenty fast enough, as the roads are mostly of rammed earth. The petrol consumption varies with the speed and going from .8 to 5.5 gal per mile.
When the tank climbs, however, (it does it in low) the speed drops to about 2 mph, which, by the way, is faster than most people can walk up hill. The tk will climb a 1 in 2 gradient on reasonable ground (say clay) provided the hill is tackled straight on, and it, was usual practice for the tp/ldr to do a ft recce and guide the tk up by hand sigs, since at steep angles the driver cannot always see the ground. Briefly, a properly driven CENTURION will climb any hill it can get a grip on. But there is a snag. The tp/ldr on his recce must make sure he has room to turn at the top, and this is NOT on narrow ridges since CENTURIONS throw tracks with remarkable ease on ridges. . (The dirt packs hard under the rd wheels and lifts them off the horns). It requires one tk length clear in front or behind to "back and fill" to clear said earth.
The 8 H had a "track charge" of 1½ lbs plastic HE with which to blow the track in such cases. A very quick and successful device. I mentioned that the tanks climb in low gear. In case this draws a horse laugh I will explain that on very steep hills the main brakes will not always hold 50 tons, so you can't change down easily.
On one occasion a tk took a run at a steep hill in 2nd gear, got two thirds up and the driver missed his gear on the change down. The tk carried all before it on the way down and, deftly hurdling,a rd cut in the side of the hill, continued up the other side of the gully. It continued to behave like a yo yo until gravity prevailed. A remarkable sight. Beyond an understandable change of colour the crew were unhurt. CENTURIONS CLIMB IN LOW GEAR. For the same reason CENTURIONS also cross paddies in low gear. Now crossing paddies is strictly by guess and by God. However, here are a few pointers. You can't tell by looking at a paddy if a CENTURION will cross it It behoves the unfortunate tp/ldr to get out with a stick and prod. I carried one for this purpose (the other end of which was used for stirring the “all in“ stew) in the cleft between the gun mantlet and the turret. Now if this stick strikes hard mud at about 18" depth most of the way across then you have a 50-50.chance. .You then try with one tk. (It is considered bad form to have all tks bogged in, one paddy). If one tk crosses the others try in turn - in different tracks. Paddy bunds are another snag, as they are often hard enough to lift the front of the tk, thus 70% of the traction may be lost. If, you got track-slip on a bund, stop, and dig away the bund with the shovels so thoughtfully provided. This work is made much easier if a gang of local peasants can be found, but be sure you get the shovels back.
While you are making progress, keep the tracks turning. If the tk stops, stop the tracks. If the combined tow ropes will NOT reach the bogged tank, do NOT put another in after it. Anyway there may be mines. Elementary? Yes, but I have seen four tks bogged in one paddy. There were only two bright spots in this depressing scene. One was the uninterrupted flow of Gaelic obscenity from the rec Sgt. and the other was the face of the tp/ldr.
Let me now speaks further word of wisdom on tracks, as they are perhaps the most constant problem on CENTURIONS. I have mentioned turning on slopes, the next pt is tightness. New the good book says there will be 2" sag between the two top centre rollers. Experience has, proved this wrong. The tracks should be as tight as they will cold, with two men on the bar. (If you tighten them hot from a run they will be over tight when cold and the front rd-wheel lift). Another pt is track pins. These require constant watching. If you suddenly hear a rhythmic clanging from one track, stop and look. You will find a track pin-head has worn off, a pin is protruding, and has been beating on the bazooka plates. If you stop soon enough, it is a simple matter to beat another pin through. Pt No 4 about tracks is that in temp below zero the tracks may freeze solid to the ground if you have more than an inch or two of sinkage. With 640 HP engine this may sound impossible, but it's true. It is avoided putting straw, brushwood or leaves under the tracks before harbouring. Further, when operating in winter, drop the bazooka plates and remove the mud from the grease nipples a soon as you harbour, this avoids hrs of work with a blow torch and a pickhead, when the time comes to grease up. Greasing shouid be done as often as possible in winter, preferably after every run as condensation takes place in air spaced and rust bearings. For this reason too, all tks in this area have a grease nipple fitted to the ring bolt that pulls fwd the idler arm to tighten the track. (Last winter some ring bolts had rusted solid on to the idler arm, with rather expensive results) (For the same reason, we grease after wading).
And now to rd wheels. We find that the pairs next to each sprocket wear out first due to large and small pieces of KOREA being thrown on to them, from the tracks, by the sprocket. A knowing eye should be cocked at said wheels from time to time, and they should be changed with the centre pair before wear becomes excessive.
A further winter warning. Make sure that the floor beneath the amn and beneath the engine and gear-box is dry before winter, even to patiently swabbing out the last drops with a mop. And keep it dry all winter, because if you don't the control rods will freeze tight to the floor. The tk may be OK (if under cover) in the morning, and freeze while you are on the move. This shakes the confidence of even the best dvrs.
While on the subject of water, a word on wading. Without preparation, the tk will wade with impunity till the water comes in the dvrs hatch (about 4 ft). Again low gear is emp, or the dvr gets a bow-wave in the lap.
There is NOT much I can say about the armour, except that I have every confidence in its high quality. CENTURIONS have withstood direct hits from 155mm HE with only superficial damage. Also, don't touch it with bare hands when really cold or you leave bits of skin on it, particularly if the hands are moist. Further, it is thick enough to keep a well placed bottle of beer cool in summer.
A few words on the effect of mines might not be amiss. A thing the size of a Hawkins grenade may crack a link but NOT necessarily immobilise the tk. 2O lbs of Mr.WU's picric acid will blow a track and a rd wheel if close to the surface. Mr. WU's normal practice appears to be 40 lbs of picric acid (2 box mines) up to two ft down. Half a sqn may go over it before it goes up, and its effect depends entirely on the ground. In one case it merely blew the bed rolls off, and the rations out of one bin. In another it took off two pair of rd wheels and three ft of track.
Beyond one case of concussion NO damage tocrews has been reported.
We have, to date NO hits from enemy AP but a 20 pr AP at 100 yds will go through both sides of a CENTURION'S turret and right through a CROMWELL or T-34 end on at 2,800 yds which brings us to
Let me state that the 20 pr is the best tk gun we have had so far once my tp spent a week sniping individual CHINAMEN at a range of 3,600 yds with a most satisfactory degree of success. (One morning we got two before breakfast). It will put a shot into a bunker mouth at a 4,000 yds, once ranging has been completed, although it may take up to three shells to put one right in. Therefore 4,000 yds is considered the economic max for pin point shooting with HE.
However, the fragmentation of the HE round is poor. It appears to fragment in strips the length of the shell. I have seen two Chows bisected nearly at the navel, it's true, but on the other hand I've also landed a shell about six ft from the heels of a fleeing Chow and he showed NO effect other than a surprising degree of acceleration.
Their effect in a confined space such as a bunker, however, is little short of atomic, as the bunkers are mostly well stocked with blast grenades whicg go off too. During op COMMANDO I poked my nose into a bunker in which I had seen a shell land. I counted five heads, some round, some flat, some attached, and some detached. There was too much mess for one shell, so I suppose a good sup of grenades went up too. It is therefore good policy to put 'em in the door where possible. The other good pt about the 20 pr shell is that you can't hear it coming. I once, as a tk OP (see Tac) got a little close to the receiving end of our own tk fire and 20 pr rounds arrive without the well known whine. They crack overhead like outsize bullets. In spite of my faith in the 20 pr and the gnrs of 8 KRIH thiss was a rather unsettling performance and is worth bearing in mind when supporting inf.
The rate of fire of the 20 pr is also good if, firstly, it is possible to "load off the deck“ and secondly the gunner and operator "fire on the trip". Loading off the deck is self explanatory, the rounds being passed off the back deck to the loader by the driver. Firing on the trip means that the gnr keeps the gun on the target and his finger on the button. The loader then fires the gun when he trips the (safety) trip switch. By this means my crew once had 5 shells in the air at once and fired 50 rounds in 8 mins. (Then the loader fainted from the fumes).
If firing intense, therefore swap the loader with the dvr at the third “clear‘out" of empties. (We normally cleared after every 10 rounds). Naturally it is NOT possible to load from the deck when moving or when incoming mail is close, and under these circumstances the rate of fire is greatly reduced after the first 10 rounds. (I carried 50 HE, l0 AP, 4 smoke per tk). There is one pt more which is well worth a mention. Wherever it is at all possible, travel with the gun in the crutch as travelling with the gun to the front causes excessive wear on the elevating gear. This results in excessive play in the page which in turn leads to inaccurate shooting. For the same reason it is advisable to stop the crew from doing chin-ups on the gun, or traversing half RIGHT and using it to pitch a bivvy. (This latter practice particularly infuriates Gasket).
And so to the Besa. Now the Besa is on the LEFT of the main armament on the CENTURION, and it has a RIGHT hand feed. The belt comes over the top of the MG and round a roller. It has NOT proved a satisfactory feed, as the belt tends to over-run, and end in a heap on the floor. These are two answers. One is to replace the roller with a metal spigot, which causes more friction; the other is to mount a bracket on the RIGHT of the MG and below it.
During the Apr battle the need for a second MG was felt, as angry little men climbed on the top of the tks and beat on the hatches with fists and rifle butts. One answer was to charge through a mud house, but this was NOT thought to be the real answer, as it increased the shortage of houses already made obvious by zealous gunners. It was thought further that it was better to stop people getting on in the first place. Therefore .30 BROWNINGS were obtained, rumour has it at high cost (in gin), and mounted on the comds cupola. This has a dual advantage in that it solved the problem of the angry little men, and also prevented crew comds from being garrotted by signallers, with their customary homicidal tendencies towards tk men. The fury of the R. Sigs knew NO bounds as their now harmless tight wire traps were time and again swept serenely aside by the advancing tanks. Personally I cherished NO animosity towards the Sigs and contented myself with merely immobilising 3/4 of Seouls tram car service by laying claim, vi et armis, to some 200 yds of overhead wire, which I took with me for some four blocks. Fortunately for me someone preceding me had touched the same wire and blown the fuze, or I might have got summary justice. It was hanging low anyway.
So much for the .30 BROWNING - a useful gun. Now , smoke dischargers. These have never been loaded since the Apr battle as a chance bullet set one off, and it dribbled all down into the engine and set it on fire. The tk was lost. I expect the Chow responsible get a MID.
It was just as well that we did NOT have to do much shooting on the move as I doubt if the Aux Gens would have stood it. Briefly the Morris Eight engine is NOT up to the job (even with the dynamo on the main engine (MK IV B) as it is grossly overloaded. We used to get an average of 35 to 40 hrs per Aux Gen, before something went wrong. But here is one tip that is worth knowing. If it can be avoided, don't run the Aux Gen when the tk is parked on a slope, as it may be steep enough to cause intermittent oil feed. Expensive noises ensue.
And that I think, about ends Part one except that even the Americans agree that the CENTURION is the best tk in our theatre to date, since it shoots better, climbs better and crosses paddies better than anything else out here so far, and I include the grossly over-rated T 34 in that.
Swans varied in str from a sqn with a bn to, more commonly, a tp with a Coy. The Inf wandered along the ridges accompanied by a tk OP offr with an 88 set and the tks waddled up the valley. If the inf got into a fire fight the OP would direct tk fire into bunkers if he could. At the end of the day the inf climbed on the tk and rode home.
SET PIECE ATTACKS:
On Swans the tk OPO was a highly successful invention. It was therefore decided to try out the same idea on Op COMMANDO, a Div Set Piece attack. The OPO moved with the fwd coy of inf. I was OPO for B Sqn 8 H and moved gaily off with B Coy of the AUSTRALIANS. But alas the best laid schemes of mice and men. In an attack of that size I found all channels of the 88 set so full that I could NOT get a word in edgewise. The tks had got into excellent fire posns in the rear and flanks of the attacking inf; in most cases they were perched on top of the dominating features, and were ready to "shoot the inf in". And NO word from the OP, who at that stage was trying to dig a hole with a mess tin and shout down AUSTRALIANS, NORTHUMBERLAHDS and KOSBs on the 88 set. The Sqn Ldr of B Sqn then took himself a 31 set and tied him to AUST Bn HQ (Tac). Said he to the Bn Comd "where would you like 500 rounds of 20 pr HE in the next l0 mins". "On that bald feature" said the CO. (It was a good 50 yds from the fwd inf). And it was so; an impressive sight. The Sqn Ldr/CO team worked so well, even under enemy shellfire, that both got a DSO. I then took over a tp.
When all objs had been sighted I found myself and my gallant 1 Tp sitting on a high feature overlooking the Chows, surrounded by the RIGHT hand fwd coy of AUSTRALIANS. There were three reasons for this. First, the Chows had NOT produced anything aggressively anti-tk. Secondly, we could hammer enemy OP dug-outs which he had on the very tops of the high features, and which the Arty could NOT hit without a vast expenditure of amn. Thirdly, the Aussies had NO intention of withdrawing, so the tks were going to fight it out with them if necessary.
And there we stayed for some 55 days in all, with an occasional trip back to Sqn harbour for a clean up and a bottle of whisky. Amn and sups were brought up on de-turreted CENTURIONS called tugs. A most useful veh.
Occasionally, when we had made ourselves too obnoxious to him, Mr. Wu treated us-to some HV HE or some fd arty. This had little effect beyond making the Aussies tell us what we could do with our (horrid word) crab drawing tks. Mr. Wu put in 5 counter attacks, but the full force did NOT fall on us, and we were finally relieved by 7 RCT who took over our sector and whose PATTONS could NOT get to where the CENTURIONS had been until some days later.
To end with just a little of the country in gen. It is difficult for tks, often the best route up a valley is in the bed of a running stream. The hills are mostly steep (but NOT over high - 2,000 ft is a high hill). To climb them requires careful recce on ft. This means that the tk can seldom aslt with, or in front of, the inf, and is reduced to the "shooting on“ role in most cases. The areas where a tk versus tk battle could take place are few, and I have NOT been in them. That is about all I can think of which may interest you on CENTURIONS in KOREA.
And now, Sir, a few words for your private ear on the T 34. I assume that the tks given by Joe to Mr. Wu are old models. Even so they were grossly over-rated in press reports in the early days of the KOREAN Camaign. (A well placed HE shell from a 20 pr will lift the turret off). Only about 4 per Sqn have wrls and their armour is of poor quality. The whole tk is of the crudest workmanship, and breaks down with the greatest ease. (In fairness I must add that this may be due to inexperienced CHINESE crew). They would have to be used in mass, RUSSIAN fashion, to be any treat to a well trained, well equipped Army, as they have been proved somewhat inferior to the SHERMAN. A CENTURION will do to them what a TIGER did to the SHERMAN. They got their initial build up as a scapegoat to cover the natural and understandable, fact that the first American tps over here were raw, frightened boys who were also soft from occupational duties in JAPAN. The T 34, I am convinced, should be de-bunked. It is a workable tk, but NOT a wonder tk.