The Life Expectancy Of A Track
 

My most recent game session has brought something into focus that I had been meaning to bring up with the Forum for some time. As you know, I'm a trucker and as such, I am VERY familiar with the life expectancy of both heavy and light vehicle tires. I have set the wear values on heavy ROAD tires at 20,000 Kms per 1 Wear Value (for a maximum range to BALD tires of 200,000km) and heavy OFF-ROAD tires at 10,000 Km per 1 Wear Value (for a maximum range to BALD tires of 100,000 km for the softer durometer off-road tires).

The problem I'm having is how to rate TRACKS by Wear Value. I have seen claims that say some tracks wear out in just 10,000 km where others can go 50,000km before needing replacement. I have some experience with the M110 series and the M113 chassis as well. A lifespan of 50,000km sticks in my mind but this does seem a bit high.

I'd appreciate the input of the Tankers here in our forum.

According to documents from 1988, the Army was getting an average of 945 miles per set of tracks for M1 tanks and 840 miles for M1A1 in actual service. By the time of the GAO's 1991 report NSIAD-91-114 Abrams Tank: Operating Costs More Than Expected, that number had declined to 850 miles for the M1 and 710 for M1A1. Both of those were with the T156 link, which was replaced by the T158 in the early '90s, adding 2796 pounds of weight to the tracks. I don't have reports on what sort of lifespan the T158 has had.

Note that this is still a great improvement on early tanks - the Mark I's treads lasted an average of 25 to 30 miles (and drive sprockets usually only lasted 20 miles).

I was led to believe that track life was very much less than tyre life and so using the info The Dark provided, we can see that track life is quite a lot less than tyre life, radically less - just 1520.8 km for M1 using T156 track and 1351.8 km for the M1A1 using the same track (and then adjusted to 1367.9 km for the M1 and 1142.6 km for the M1A1). I wasn't expecting it to be so little in comparison to tyres.

While obviously the more complex & mechanical design of track has more components to wear out and cause problems, I would have expected metal components to last longer than that.
Without information to the contrary, as a completely unqualified guess, I think you could argue for a general estimate of track life as 15% of off-road tyre lifespan provided by swaghauler - and that's on the generous side, using the figures provided by The Dark, it's more likely to be 11%.

So: -
heavy road tyre - 20,000 km (bald)
off-road tyre - 10,000 km (bald)
generic track - 1500 km (unusable, except as ad-hoc armour)

P.S. swaghauler, I think I finally understand your choice for forum name now! :D

Found my old field manual for the M110 and tracks are to receive a complete replacement at 1000 miles with trackpad replacement every 500 miles (our tracks had the rubber inserts), so The Dark's estimates are probably very close. This is considerably lower than I had anticipated. That makes wheeled APCs seem much more appealing when you consider how many miles you can get out of heavy truck tires. I know we swap out our tires at 100,000 miles on average (the guys supplying oil fields get fewer miles because the "non-super slab" highways are much rougher), and that's with 20+ ply tires that still have 1/8th an inch of tread. Even then, changing all 18 of the tires on a big rig will run you from $7K to $10K depending on the weight rating of those tires (heavy hauls handling more than 80K lbs gross vehicle weight can get REALLY expensive, as can Super Singles like the Army uses).

I wonder where the characters will find new tracks with a wear value increase every 100km to 150km. Just think about that range in the context of driving across California, Texas, or Poland. I wonder how many AFVs "threw a shoe" when their tracks wore out?


StainlessSteelCynic: I have had a very strange career. First, I grew up on a beef cattle farm driving tractors, welding, and learning skills that would probably make a "Prepper" jealous (canning, welding, tanning, rendering animals, and butchery). I then graduated high school and started my career by going to college (with our Forum's own Admiral Lee no less). I joined the Army Reserves to pay for college and because EVERY man in our family, WITHOUT EXCEPTION, has served in the Military. I was a Cannon Crewman there until we were disbanded in 1991 and I was retrained as a 77F (petroleum specialist) and eventually also as an 88M (heavy wheeled vehicle driver). I graduated (Criminal Justice with PA 120: Municipal LE) and went to RESTORE HOPE where I drove a Truck (HEMTTs and 5-Tons).
I then got off of Active Duty, came home, and joined an Armored Car company. I got my CDLA AND drove a big Truck. In essence, I drove people's SWAG (good/valuable stuff for those who don't know what "SWAG" means). SwagHauler was my call sign. I worked with guy's "call signed" Wrongway, Loose change, Big Green, and Crashbox, so it could have been worse.
Several months later, I then joined my County Sheriff's Department. I continued working armored cars part-time until I retired in 2012. I had also worked installing safes and fabricating vaults for several years (the company I drove armored cars for also built banks and depositories and they found out I could weld). There was that short "collaboration" with Dave (growls quietly). Dave convinced me that Protective Specialist work was the future. This was in the early 21st Century and the PMC craze was sweeping America. If you were ex-military or LE, they were paying big money for your services overseas. James Yeager was a PMC when he had his ONE shootout. So was Joe Teti of Dual Survival fame (or "infamy"). He convinced me to take a couple of trips to Africa (expending all my County vacation time) protecting young Christians on Missionary. Those trips SUCKED! I found out Dave was long on talk and short on planning. He also wasn't as good under pressure as I had hoped. He SERIOUSLY CONSIDERED shooting his way through a (then new) Boko Haram roadblock with just two single-stack 9mms loaded with ball ammo! He did give me one good trip to Afghanistan as security for a bunch of businessmen selling equipment to the new government.

When I retired from the County, I decided to become a "chains-for-brains" and have been driving ever since. In truth, Trucking SUCKS. the money just isn't there for the hours over the road. It does give me time to write and plan adventures though.

PMCs can be really shoddily run. There's a book called 'The Circuit' that covers this.

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T158 is supposed to be good for 2,000 miles of highway use. An extended range version is supposed to be good for up to 3,000 miles, planned for introduction in 2020-21.

Ah, that fits with a line I saw that was comparing the M60A3 and M1 tracks, but I wasn't sure which tank it was referring to. According to what I read, the 2000 miles of highway use was equivalent to 800 miles on gravel or 250 miles cross-country.

I am not saying that is wrong, but it does not sound correct. Driving on the streets was much harder on the tracks when I was in Armor, or at least it looked like it to me. We sure left a LOT more rubber on the road, every turn massive rubber skid marks (and/or torn up road). Shortly after I got to my first unit we went on a six week field exercise and my TC had me driving all day long to get me up to speed. By the end of the year I had enough miles to get my drivers badge - T, and we did not change the track that year or the next. (Maybe the mechanics did, but that does not sound right to me either).

It's the other way around, paved roads tear up rubber track much faster than dirt! Exception is if you are driving across lava beds or rock. Tracks are primarily designed for off road use.

I was active duty tanker for over ten years, only changed track on an M-1 once and that was because of a new design track. On M-60A1/A3, we had to replace track pads as needed, but we quickly learned to give the head of the screw a love tap to mushroom so the nut would not vibrate off.

That was one thing that I am betting a lot of people overlooked during the game - we played one campaign where we made damn sure that every time we found a vehicle with any track segments left that could be salvaged we grabbed them specifically to keep the tracks in good shape - throwing a track or having your tracks go bad is one of the fastest ways to convert an armored vehicle into a permanent pillbox if you dont have track segments and parts to repair it with

From US prospective, a track block is a single metal and rubber section, weighing between 80-90 pounds, depending on type. It has three connective pieces, the centerfield, which keeps the track aligned with the road wheels and two end connectors, which each end of the block. These three connectors are used to link each block to the next.

Wear wise, the block itself is worn by decay of the rubber due to age, wear on hard surfaces or battle damage. Centerfield take quit a bit of wear before needing replacement, typically battle damage or "throwing a track" will result in 3-4 centerfield needing replacement. End connectors slip over the ends of two blocks and are locked in place with a wedge and bolt. While "Der book" doesn't mention this an old tanker trick is to tighten the bolt and then use a ball peen hammer to mushroom the bolt so that it doesn't vibrate loose.

Of all the track components, the end connectors cause more problems due to the bolt/wedge vibrating loose. It is common for 2-3 of these to be lost on long road marches.

It is unit SOP to carry 1-2 sections of track (usually four blocks already connected together) and a half dozen centerguides and a dozen or so end connectors, just in case.

One of the oddities of US units in Germany, was a controlled scavenge point for the tank battalions, as tanks were rotated back for refurbishment or factory rebuilds, it was normal practice to remove tracks and road wheels, especially if they were in new or almost new condition. These would be stored near the ammo supply points and would be cannibalized as necessary.

It was also common practise, when a tank was being turned in, to replace all functioning equipment with defective equipment from deadlines tanks. With factory rebuilds, this equipment would be refurbished or replaced with new equipment, and if it would increase the battalion's runners...

Tankers were always creative about "acquiring" additional equipment by fair means or foul, in other words, midnight requisition, ruled! My first tank platoon was equipped with M-60A1s, each fitted with searchlights, in our Motorola conexs, we had an additional three headlights as well as night vision and rangefinder spares, air filters for the engines and enough excess field gear to outfit a platoon!

My first tank section had IPM-1's and one day as we conducting drivers training we drove past a "new" tank park full of M-60's. Later asked what it was for and was told they were waiting to be moved to the range to be hard targets. That night we went back and "acquired" some extra parts for our firing system (I still have one of the "extra" firing pins).

Ahh, most units I've been in have a special depot for exactly that purpose -- we called it the "Can Point" (for cannibilization point). We not only got vehicle parts -- we got things like the Claymore mine bag I had to carry my toiletries to the latrine, an extra med bag to carry double the medical supplies or some extras to carry some med stuff I found in town (this was after I became a Combat Lifesaver), a light tarp for a ground sheet or as an improvised shelter, etc. We all loved to go to the Can Point; unfortunately, they weighed your vehicle afterwards, and the stuff came out of the Brigade budget; if you just went crazy instead of being selective about what you were taking, the you might get a visit from the Brigade XO or one of his minions...

As a little addendum; long grass rips up road tyres quickly

So does a lot of tight turns in rapid succession (like when doing a Sagger Dance).

I'm with you and CDAT. I never changed a track either. I did have to replace those rubber track pads all the time too, at least on the M110 (the M113s didn't have this issue).

Suspension Wear Values
 

Ok, I think I'm going to set each increase in Wear Value at:

Heavy Commercial Truck Tires: 1 Wear Value per 16,000Km for a total of 160,000Km on a set of Heavy Commercial Tires.

Heavy Super Single Off-Road Tires (ie HEMETT and 5-Ton tires): 1 Wear Value per 10,000Km for a total of 100,000Km on a set of softer Durometer Off-Road Specific Super Singles.

On-Road Motorcycle Tires, Touring: 1 Wear Value per 8,000Km for a total of 80,000Km on a set of Touring Tires.

On-Road Motorcycle Tires, Performance: 1 Wear Value per 5,000Km for a total tire life of 50,000Km on soft Durometer/High Traction Race tires.

Off-Road Motorcycle Tires, DOT Approved: 1 Wear Value per 5,000Km for a tire life of 50,000Km for the soft durometer Off-Road Motorcycle Tires.

Passenger Car/Light Truck Tires, Economy: 1 Wear Value per 12,500Km for a life of 125,000Km.

Performance Tires, Sports Car: 1 Wear Value per 8,000Km for a total of 80,000Km on soft durometer/high traction Performance Tires.

Tracks, Armored/Commercial: 1 Wear Value per 1,000Km for a total of 10,000Km per Track.

This all assumes proper maintenance of the suspension and no "battle damage" or "terrain related damage" (failed driving rolls) which can also increase Wear Ratings.

For the record, I'm currently breaking down Vehicle Wear Ratings into Four Catagories. Engine & Transmission, Suspension, Body, and Peripherals (electronics, optics, and weapons).

We've has SO MANY discussions over the years about which parts would wear out, which would have to be modified or regularly replaced if we went with canon T2K's reliance on alcohol as a fuel, what tends to fail as a result of wear and tear or battle damage. In terms of tracked military vehicles, it seems to me as a result of this discussion that a lack of spare, low-wear track components would be the biggest killer of MBTs and IFVs by far.