tank mechanic

6

Flow Visualizations

Spread across the world are a legion facilities that allow the creation of artificial oceans ( wave tanks ) which are used for experimenting with surface waves. From testing simple parts for behavior to comprehension of complex flow phenomenon in oceans and seas, wave tanks are freaking awesome!

And how they work is simple:

At one end of the tank an actuator ( those giant hands that are moving in unison ) generates waves; the other end usually has a wave-absorbing surface.

Pretty cool eh?

Sources: Edinburgh University  Jason Truscott dantheman733

Tanks M4A2(76)W “Sherman” of the 1st battalion of the 46th guards tank brigade 9th guards mechanized corps of the 6th tank army on the streets of Vienna. This tank battalion under the command of guard captain D. F. Vine, breaking 100 kilometers, a number of barricades and nodes of resistance, 9 April 1945 broke through to the centre of Vienna and held it until the main forces brigade. The detachment was 18, “Sherman”, 3 ISU-152 and a company of Marines to 80 people. D. F. Loza received for this fight the title of Hero of the Soviet Union.

Laid off to give my work to foreman's girlfriend and waste three years of my life? Cool enjoy the OHS fines!

So a month ago our shop foreman got his girlfriend hired into the parts department, which was separate from his department. She started complaining she was bored and didn’t have enough work. Out of the 7 people in my department, five of them stood around talking all day, one was management busy doing daily paperwork and lastly was myself who was kept so busy doing four other people’s positions after they were laid off. I hardly had time in a day to take my own lunch break to keep up with my daily duties. Anyways.

She started complaining to management that she wasn’t busy enough in a day and wanted more work. Management never once asked me if there were any duties I could pass on to keep her busy, which I would’ve gladly handed some over. A week after she was hired I was sat down and given a layoff notice for “not enough work” and economic slowdown. I’d been there for three years and the manager had Told me only two weeks prior to the new hire that I would get to enroll in my apprenticeship this month. He obviously had no intention of actually following through on my apprenticeship, which now three years worth of practical hours were wasted. They were going to shove all of my duties onto the new girl, also forgetting I was the only certified forklift operator in the building and had to unload freight trucks all day in between other duties.

So the day after my layoff takes effect, I call into occupational health and safety and call in every single infraction that I saw over the course of my employment and really drove home the point of now they don’t have a forklift operator which is a huge fine in itself. Also reported mechanics smoking less than a foot from a dirty oil disposal tank, mechanics without appropriate drivers license driving class 1 vehicles outside of the lot, improper storage of dangerous and hazardous materials, improper use of grinding and cutting equipment without appropriate safety equipment, employees climbing and scaling racking in the warehouse, uncertified employees fork lifting other employees on the forks of the forklift without harnesses or man-basket, no safety procedure for evacuation of building or muster points and lastly letting people who’ve been stripped of drivers licence for medical reasons drive company vehicles off the lot and drive heavy equipment in the compound. I was also able to provide photographic and video proof of most of these incidents.

OHS called me back after reviewing the information and informed me that they had passed on some of the infractions (driving ones) to RCMP to review and that both the documented drivers and well as the company would receive charges for these. As a result of my report the business operations are suspended until further notice to give them time to get everyone certified and licensed appropriately and are facing some very heavy fines.

There are twelve mechanic bays and one alone down for a day makes the business loose $5000/day. That’s $60,000/ day losses in revenue for just the shop and about $20,000/day for parts department. $80k losses a day in revenue plus upwards of $100K in fines and certifications costs.

BONUS: the manager was fudging the employment application numbers to make it seem like there wasn’t enough certified locals to employ so that he could bring in people from his home country- England. I also called the provincial and federal immigration and employment offices and reported what he was doing. Currently we would get upwards of 100 journeyman resumes a week for the last year and he brought two Englishman over in the last 6 months who were first year apprentices. No one Currently employed faces deportation but the company as a whole will have importation of labour freeze for up to ten years and also faces major fines for falsifying information that led to importing workers.

3

An Oregon judge has allowed a 52-year-old retired Army tank mechanic to change gender identity. Not from male to female, or vice versa. But to a new, third gender.

Jamie Shupe is now legally non-binary — widely believed to be a first for the United States.

Oregon joins several countries in recognizing a third gender. In 2014, India became the largest country in the world to have an official third option, following in the footsteps of Pakistan, Australia and Germany.

Shupe was born male, got married and had a child.

“I was in a deep, dark depression because I had boxed myself into this male identity that I couldn’t stand anymore,” Shupe says.

Three years ago, Shupe decided enough is enough.

“I told family members, we either let me out of this box or I’m shooting myself in the head. Things really got that bad,” Shupe recalls.

Shupe is no longer legally male or female and prefers the pronoun “they.”

Neither Male Nor Female: Oregon Resident Legally Recognized As Third Gender

Photos: Kristian Foden-Vencil/OPB News

10

U.S. Marines with the Combined Arms Company, Black Sea Rotational Force, Bulgarian and Romanian Forces conduct a joint exercise utilizing Bulgarian and U.S. main battle tanks, indirect fire, mechanized infantry, and close air support from U.S. Air Force assets during Platinum Lion 16-2 at Novo Selo Training Area, Bulgaria, Jan. 15, 2016. (U.S. Marine Corps Photo by Cpl. Justin T. Updegraff/Released)

6

Overview of Tank Mobility

Tank mobility can be broken down into three types, tactical mobility, operational mobility and strategic mobility. Tactical mobility is a tanks ability to move about a battlefield. Operational mobility is a tanks ability to move about the Area of Operation. Strategic mobility is the tanks ability to be moved to the AO. Mobility traditionally forms one of the three corners of the tank capability triangle, with the other two corners being armour and firepower. The mobility of tanks is one of the features that has made them so important on the modern battlefield.

Tactical Mobility

Tactical mobility can be broken down into two major categories, agility and obstacle clearance. Agility encompasses a tanks acceleration, deceleration, turning and top speed. Obstacle clearance includes a tanks ability to cross trenches, walls and move over rough terrain. This mobility is provided by a tanks engine and its tracks.

Engine

Tanks are universally powered by internal combustion engines. Almost all tanks from the first combat tank, the Mk. I, through the modern Leopard 2, use diesel piston engines, with most using inline engines. Some tanks have employed radial engines due to their improved power-to-weight ratios and greater reliability. Radials were included on many WWII era American tanks including the M3 Stuart and some models of the M4 Sherman and M3 Lee.

Some modern tanks employ high power turboshaft engines. The M1 Abrams mounts the Honeywell AGT 1500, a multi-fuel turbine engine that produces 1,500 hp. The only other tank to be powered solely by a turbine engine are certain models of the Russian T-80, though some models have been modified to mount a diesel engine to improve fuel consumption rates. Some tanks including the Swedish Stridsvagen have both a piston and a turbine engine, alternating between the two based on the situation at hand.

Tracks

Tanks use continuous or “caterpillar” tracks for propulsion. Continuous tracks allow for improved performance on rough terrain by virtue of their lower ground pressure and higher overall traction. Tracks are made up of a chain of interlocking metal pieces which orbit around the track assembly. Track assemblies are made up of a series of wheels which keep the track running smoothly.

  1. Drive Wheel (rear wheel drive)
    Connects to engine and moves the track.
  2. Track
    Moves across the wheels in a continuous motion.
  3. Rollers
    Keep the track aligned with the drive wheel. Some arrangements forego these entirely, instead allowing the track to droop onto the road wheels. This is known as a slack track arrangement.
  4. Drive Wheel (front wheel drive)
    See #1.
  5. Road Wheels
    These wheels transfer the load to the ground. Road wheels are generally attached to some form of suspension which allows a smoother ride. 
  6. Idler
    This small wheel is used to tension the track to marginalize the chance of the track becoming detatched from the assembly.

Many military tracks use metal links with a rubber shoe, this allows for good traction while preventing damage to both the ground that the tank passes over, and the metal links themselves. The shoes are easily replaceable. Pictured below are two new pads and two old worn pads on an M1A2 tank. 

Operational Mobility

Operational mobility encompasses a tanks ability to cross larger obstacles such as rivers and minefields during movement around the AO. Engineers have invented a variety of ways of dealing with each of these obstacles. 

Rivers

The two main ways that tanks cross rivers without pre-exsisting crossings is by fording or with bridge layers. 

Fording

Fording a river means simply wading across it. The main consideration when fording, is ensuring that the tank does not go so deep as to cut off oxygen to the crew and engines. This problem of keeping engines supplied with oxygen is familiar to submariners and a familiar solution has been employed. While many tanks can only ford rivers that are less than about 1 metre deep in their stock configuration, some tanks, including the Leopard 2, can be fitted with a vehicle snorkel to allow for the crossing of rivers deeper than the vehicle is tall. This technology was pioneered during WWII by both the Axis and the Allies for different reasons. The technology was developed by the allies to optimize tanks for beachhead invasions by allowing them to be offloaded from landing vehicles far from shore, then swim up to the beach. Pictured below are two Sherman tanks fitted with snorkels over their intake and exhaust.

The Nazis developed a similar technology out of necessity. Early in its development, the Tiger tank was found to be simply too heavy to cross most bridges in Europe and so it was almost always forced to ford when a river was encountered. The problem was that, despite the Tigers height, many rivers were simply too deep to allow for effective fording. The solution was to attach a tall tube to the turret and and seal all openings with rubber gaskets. This allowed oxygen into the compartment and prevented water from seeping in.

Many modern snorkels are wide enough to double as escape hatches in the case of a mechanical failure while the tank is submerged.

Bridge Layers

The need for armoured bridge layers became apparent during WWII when blitzkrieg forces needed to move rapidly across terrain including rivers without leaving behind other mechanized units and without concentrating forces on a few available bridges. Modern bridge layers build on this doctrine by allowing efficient operational force deployment in areas with little to no infrastructure. One such vehicle, the American M104 Wolverine, can deploy a 26 metre bridge that can support up to 70 tons in as little as 5 minutes.

Minefields

Minefields, in general, pose less of a threat to modern military vehicles than they once did, however, minefields can still immobilize even the most heavily armoured vehicles and they can still pose a lethal threat to personnel and light equipment. There are two main ways of clearing minefields employed in the modern military, mechanical and explosive.

Mechanical

There are two primary mechanical mine clearing methods, the flail or roller, and the plow. The roller, invented during WWI acts by placing pressure across a large area in an attempt to detonate any mine it passes over. These rollers are largely invulnerable to the explosions and are placed far enough from the vehicle that carries them to keep the vehicle from being damaged. The main disadvantage of a roller is that, on uneven terrain, it may only put pressure on part of the ground, leaving some mines untouched. The solution to this problem was the flail, developed during WWII and still in use today. The mine flail consists of a large rotating drum to which lengths of chain are attached. When the drum is spun the chains whip around impacting the ground evenly and causing mines to detonate.

This method can be very effective, but in order to effectivley clear the area, the flail must move slowly. The mine plow is simply a heavy plow that overturns the earth and pushes mines to the side. This method can clear a path but may leave many mines undetonated.

Explosive

In a combat situation, when mines must be cleared quickly while under fire, the Mine Clearing Line Charge (MCLC) or “Mick-Lick” is often deployed. The MCLC consists of a series of explosives attached to a chord which is, in turn, attached to a rocket. When fired, the rocket travels across the minefield laying the explosives along a path. When the explosives are detonated, any mines along the path are also detonated. This method is fast and effective and has been used since WWII.

Strategic Mobility

Strategic mobility essentially boils down to transporting the tank. On a strategic scale, tanks cannot generally transport themselves. The tread system and low fuel efficiency of their engines mean that long distance travel under their own power is difficult and expensive. Instead, on long journeys, there are a variety of vehicle that allow tanks to be transported by air, land or sea.

Air

While not the most efficient way to travel, tanks can be carried by air. As an example, the American C-5 Galaxy can carry two M1 Tanks while the CH-54 can carry a tank under slung.

The main advantage to this type of transport is its speed and versatility. Helicopters especially can deliver tanks to places where they would not normally be able to go. The biggest disadvantage is the cost. Moving 100 tanks by air is an extremely fuel consumptive operation, and moving hundreds across the Atlantic would be a logistical nightmare.

Sea

Most large scale, long range tank transport is conducted by sea and most sea transport is conducted by Large, Medium Speed Roll-On/Roll-Off ships. These ships allow tanks to be easily loaded and transported on long ocean journeys.

Another key mode of strategic mobility, in use by countries such as Japan, the US and Russia, is the Landing Craft Air Cushioned (LCAC) known colloquially as the hovercraft. These incredible machines allow insertion of tanks, infantry and other fighting vehicles onto about 70% of the worlds beaches, including those that cannot accommodate traditional amphibious landing craft, such as swamps, marshes and soft sand beaches. Their high speed and ability to transport fighting equipment across beaches and not just to them makes these craft essential peaces of equipment for any amphibious invasion force.

Land

While tanks are able to propel themselves over land, most forces prefer to use special tank movers when covering any long distance. An excellent example of this type of vehicle is the Oshkosh M1070 Heavy Equipment Transporter. In production since 1992, this transport can carry up to 80,000 kg and is the main transport used to carry the ground vehicles of the US armed forces. There are 3 and 4 axle versions.

Trucks work well for small numbers of vehicles or in areas with little to no infrastructure. However, in many places, including inside the US, tanks are transported via train. Pictured below is a a train laden with M1A2 Abrams Tanks and Bradley Fighting Vehicles travelling through downtown Los Angeles last summer. Also pictured is me with my favorite hat and my friends dog that got tired.