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120mm main armament used on Chieftain MBTs.

120mm Blowback

As an ex-tankie (3RTR) long are the memories of the trials and tribulations all tankies go through on prepping for that dreaded time in the regimental year - annual range firing! It looms over the horizon on all crews, young and old, eager to bite the arse of those who are not prepared for what must come.

It's at times like these that the regiment seems to go into warp drive - preparing every single nut and bolt. Turrets are stripped bare, everything is cleaned, painted, inspected and fully reassembled for the task in hand. Main armaments are stripped and cleaned for the umpteenth time, GPMG mounts and link chutes checked, sights cleaned etc. The list goes on and on in the time honoured ritual.

Then SIM training kicks in: turret crews rattling around inside like demented gerbils trying to do their utmost to impress the Regimental Gunnery Instructors (RGIs) and Commanders trying to remember their words of command. Gunners flapping to get onto that target and range accurately - fingers on the hand grips clicking the buttons. Right ammo selected? Am I ready to lase? Just a gnat's more to the right. Mustn't forget to end my lay in elevation - the brain is a blare.

And finally the Loader - the guy who it all falls down to in the end to complete this symphony of noise, action, sweat, cracked knuckles and blood (if he does it right), just to get a round up the pipe in about four milliseconds on a good day.

Hovering at the side of the turret like a sprinter in the blocks ready for the gun, the word of command is screamed out by his Commander, who by now is a screaming animal, "Ranging HESH tank on!", and off he goes. Grab the nearest HESH round like you are going to strangle it, throw it into the breach, vent tube, gotta get that bloody vent tube in, SLAP! CHUNK! In it goes.

The clock is ticking. Bag charge next. Gotta be quick, gotta be slick, which one did I prep? THAT ONE! Flip the lid, grab the handle, good yank and out it comes, Christ! Forgot how long these buggers are. Flip it over, make sure it's the right way round, get it in the breach and shove till it hurts.

Back around the side of the gun, tick tock, tick tock. Grab the breach lever and pull like you are going to rip it off... CLANG! Breach closed, nearly there. Grab another HESH, cradle it like a baby, pull the safety shield closed. God! This is taking forever. Safety switch! SAFETY SWITCH! LIVE! Slap it like an unruly child and finally... finally scream "LOADED!".

Heart pumping, adrenalin racing, you hear a feeble muffled voice from the bowels of the turret: "Lasing! Firing now!" A cacophony of mechanical noise and your best effort trundles its weary way up the barrel to be deposited in the basket outside the SIM turret, and then repeat the process because the Gunner made a complete hash of the shoot.

The Gunner moans that you are too slow; the Commander moans at you both; the RGI looks at you all in disdain. "I hope you are going to do a lot better next time around, my gran moves a lot quicker than you shower. Commander, get a grip of your crew, not impressed!"

The anguish, the embarrassment, the name calling, your best just wasn't. And so it goes on and on. Don't worry though, you can watch the rest of the crews get exactly the same treatment, as the smug smiles turn to looks of failure. RGIs can NEVER be impressed. Surprised maybe, but never impressed.

And so with these happy? memories your intrepid storyteller set sail (literally) for those beautiful ranges at Castle Martin in Welsh Wales. The regiment, the whole kit and caboodle, went on low loaders from Tidworth to Southampton, on to Landing Craft Tanks and went for a little jolly round the South coast to Wales, Pembroke actually. Then a nice little drive through the sleepy town to the ranges.

What a memory that was, typical Chieftain traits: clouds of blue diesel smoke, oil covering the engine decks from yet another leak, ooops! White smoke - coolant getting burnt there; cracked liner - somebody is going to be a busy boy, until we finally arrived and got shown to our respective stands by our SSM.

Final shutdown checks. Everything ready for tomorrow, no? Boresighting! Now? Here we go again. Gunnery heads on, all the Commanders standing on oil drums peering through the boresights at that bloody dot on the boresight screen - screaming at their Gunners to take their readings and make sure they get them right. Check this, check that, are you sure? Hhmmmmm! Are you REALLY sure? Did you end your lay in elevation? Well it doesn't look like it from here! DO IT AGAIN!

Until finally when the commander is happy that the boresight dot is where it should be does he finish up and then start on the Loader. "No fuck ups tomorrow, or the world will fall on your head!" Bloody hell! I'm READY! Let's get bombed up and I'm ready to rock and roll.

Along come the lads from MT dishing out the goodies. Thank the stars we didn't have to unbox all that lot, what a pain! Here we go, what we got? 10 boxes 7.62mm, 15 SHPRAC, 4 HESH (Oh goody!), 7 DST, vent tubes, plus a couple spare... and bag charges. Great! Got the new fibreglass ones... wait a mo'... aaahh crap! Got some of the old cotton ones. Keep them in their liners, no way I'm getting bounced for a damp bag charge.

Every time. It's like moving house: stow those there, no there's better, won't have to stretch as far, GPMG boxes stowed everywhere, what are we vaporising with this amount anyway? Live HESH off to one side, keep 'em together. Got no space now. All of a sudden it's got very cramped in here. Done? OK! Scran! Whaddya mean guard duty tonight? Oh that's just peachy. Thanks for volunteering me sarge, might as well stay here, see ya bright and early!

And so after a long but quiet night along came the dawn, and with it that horrible feeling in the gut. No, today was not going to be a good day.

Here's all the lads, usual banter. Quiet? Good stag? You look tired! Haaaaaa! Piss off! And then it's down to business: safety briefs, who does what, what's where, do this, DON'T do that etc. And then the dreaded words... CREWS MOUNT!

In a scene that would grace any decent war movie the squadron sprint for their charges like knights of old. tTere go the drivers down their holes. Won't see PUG-H for a few hours and in we go: gennie on, power on, radios up and running; gun kit powering up, flying round my side of the turret double double-checking I've got everything just where I need it: trusty screw driver just in case the link chute gets jammed up, crap design if ever there was one.

Radio check! Yup! We are all here! Wait for it! Wait for it! ACTIOOOOOOON! And away we go. Check, check, check, recoil buffer? That's fine. Load the vent tube mag? No GPMG today? OK! Look up the tube, see blue and green, BORE CLEAR! And... RELAX!

"We've got SHPRAC first! 'Bike' [me] stay focused!OK?" I nod my head thinking what the hell am I doing here? "No probs boss!"

The RGI, I know he's about on our tank, can't see him, BASTARD! I've only got to fart in the wrong place and he's crawling all over me. What's his problem? It's not like I'm going to blow us up! Prophetic words! If only I'd known!

"RIGHT! STAND BY!" Here we go, hand already starting to pull a big blue job from the rack. "RANGING HESH TANK ONNNAAHH!!" "OOOOOOOONNN!" Throw it in, come on, vent tube, vent tube, SLAP CLANK! OK, bag charge. Flip the lid, quick jerk, hello my beauty! Nice and dry, red end to me, shove it all in, feeling like a vet with my arm up a cow's backside. Back round, yank the lever CLANG! Grab the next round, come on you twat! Shove the shield shut, slap the safety "LOADED!"

"LASING!... FIRING NOW!" WHOOMPHH! The old girl sits on her arse and away the first one goes. The breach seems to recoil a fair old way, but nothing's fallen off (Recoil Indicator) and around I go with the next one. Aaaaahh! The warm smell of burnt cordite. Shove it in, vent tube - at least it's not jamming like last time - next bag charge, yep nice and dry, shove it all up. "COME ON 'BIKE' WE'RE WAITING!" What's he want? Miracles? Here I am, a size 9 guy in a size 6 hole. Gimme a break will ya? Close the breach, CLANG! Grab another blue job, close the shield, slap the safety switch, "LLLOOAADDEEEEDD!" "FIRING... NOW!"

At this precise moment in time just as the electrical current has gone from the gunners trigger through the BREC to the vent tube and started the ignition process, little did I or my fellow crew members realise just what was about to happen.

The vent tube ignited as it was designed to do. The white hot gases were channelled to the igniter pads on the rear of the bagcharge. The igniter pads spontaneously combusted raising the temperature and pressure in the breach whereupon the main cordite charge fired up - raising the temperature to thousands of degrees and the pressure to tons per square inch.

All of this process was fine... except for one tiny flaw - caused unwittingly by yours truly. In the process of closing the breach I failed to notice that a small cotton thread from the bag charge a little over an inch long had become trapped in between the seals in the breech. Like electricity, the hot pressurised gases like to find the easiest way out, and this they did via the little piece of cotton... and with a vengeance!

Back to the turret: "... NOW!" Instead of the usual muffled bang, the tank then lurching back and the breach recoiling, the scene inside the turret became surreal. I have this image etched on my mind of the breech block recoiling in slow motion like a SIM resetting itself and a finger of flame - bright pink in colour and maybe a foot long - waving directly upwards and making what I can only describe as wet farting noise, but the HEAT!

They reckon that for a few tenths of a second the temperature in the turret went up to around 3500 degrees! I can testify to that. The flame disappeared as quickly as it came. A stunned silence rose in the turret. Just what the fuck was that? Why were my Gunner and Commander staring at me? Why are they white? What happened to Pete's [my Commander] moustache AND eyebrows? Just what the fuck is going on? This is not good!

"EVERYBODY OUT NOWWWWWW! BALE OUUUTT!" The words hit me like a slap in the face. Like a prat, I gently placed the round I was carrying back in its cradle like I had all the time in the world and proceeded to clamber out of the turret on to the back decks with the rest of my crew - to be confronted by half the squadron running to our tank and asking are we all right? Do we need first aid? Anyone hurt? No! Feel fine - a little singed, but otherwise fine!

I looked at our RGI. I didn't know if he was going to belt me or hug me. "I THOUGHT I'D NEVER EVER SEE ONE!" What is he rambling about? "FLASHBACK! YOURS! MY FIRST ONE!" You'd thought he'd just had a baby. Pete on the other hand looked like he could kill me. "WHAT DID YOU F****N' DO? FIRST MORNING! SECOND ROUND FIRED! WHAT'S YOUR NAME? DEATH?"

The shame! I had wanted to do so well. What could I say to him? But I hadn't a clue as to why it had happened. I'd loaded hundreds of rounds - and fired just as many - all without incident... until today. We climbed down and left the vehicle to it's own devices. No fires or anything, but just to be safe, everyone else closed their hatches. Better in than out.

"Bloody hell 'Bike'! Did you see your round go down the range?"

"Eh? No. Bit busy at the time."

"It must've gone 400 metres!"

"No shit?"

"Honestly! We were all wondering how you did it? Did you see the flame come out of your turret? It was huge!"

"Erm... I was in it at the time."

"Bet you're in the shit now, eh?"

"I think they'll have to bury me twice!"

And so the banter, accusations, finger-pointing and excuses went on. Only after the fitters had stripped the obturators (breech seals) from the gun had the culprit been brought to light. All that gas and flame had come through a tiny channel about half an inch long and maybe two to three millimetres wide. I got bollocked. I expected to. No MN&D, would have cost thousands!


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