Minecart

Minecarts are rideable objects placed on rails that are used to carry items, mobs, and the player. They have practical uses, as they can cover long distances much faster than walking. Additionally, they are used for recreation - intricate roller coasters have been created through clever track placement and design.

Minecarts are placed in the same manner as other blocks; however, they can only be created on top of minecart track. Once placed, they may be derailed by pushing them off of the end of the track. Unlike boats, minecarts are not buoyant, and thus cannot be used for water elevators.

Crafting
Minecarts can be crafted via the following formula:

Minecarts are non-stackable.

Once placed, minecarts can be destroyed and reverted to a carriable item, even while being ridden. Stone (or better) swords revert minecarts in one hit with no decrease in durability, whereas wooden swords require two hits. Two arrows suffice, but they will be lost just as if used on a mob.

Trivia

 * Minecarts appear to float above the track, as their model has no wheels.
 * Pigs can be ridden while in Minecarts, although a saddle is needed. This gives you a self-propelling minecart (see, below).
 * Small slimes may be used to power a minecart by hitting it from behind. This strategy works fairly well, and can be used to power long minecart trains.
 * Minecarts automatically stored items until the storage minecart was put into the game.

Basic Minecart Usage


Minecarts can be ridden by right-clicking them. Once inside, the player cannot move, so an external impulse (a powered minecart or booster) is required to set the cart in motion. It is possible to push the minecart manually and then jump in.

Players can exit the minecart by right clicking it, however if there is only one block of headroom above the cart the player will take half a heart of damage as he bangs his head on the ceiling. It is possible to interact with the environment while riding a cart, such as shooting a bow at enemies or laying down track in front of the minecart while it is moving.

After rolling off of the end of a track, a minecart can be pushed around on open blocks. If a minecart is pushed onto or falls onto tracks, it will "snap" to those tracks. When riding a falling minecart, landing will deal no damage.

A minecart will stop when it encounters a dropped item, and will not travel past it. If either passive or aggressive mob is hit or pushed into a rideable minecart, the minecart will stop and the mob will ride it. They will escape if the player right clicks to ride it themselves (pushing out the animal) or if the cart is destroyed. They may also exit after a while.

Speed
The physics of minecarts have been noted to be very unrealistic.

Minecarts have a predefined speed limit of 8 m/s per axis of travel. undefined This means that a minecart traveling on two axes will travel faster; for example, a sufficiently boosted minecart traveling diagonally will move at 8 m/s on the x axis and 8 m/s on the z axis, resulting in an actual speed of 11.314 m/s. This also applies to carts moving downhill (and uphill, if they have been properly boosted)

Boosting
Minecarts act very strangely when they are next to each other - they accelerate rapidly. This effect is used to create boosters, dedicated minecarts whose purpose is to provide a boost to another minecart intended to travel for long distances. When two or more minecarts are next to each other on parallel track, they will accelerate up to the speed limit and continue to accumulate energy as long as they are next to each other.

The speed limit mentioned above is applied after calculating the speed gained by boosting. When a minecart is boosted past its speed limit, it will have an "internal" speed that is higher than the speed limit, but then the game intervenes to lock it to the speed limit. This means that, until the excess energy has bled out, a sufficiently boosted cart on a straight line will continue traveling at 8 m/s and will not decelerate.

A similar effect happens on minecarts traveling downhill, if the minecart has a rider. Riderless minecarts decelerate rapidly after reaching the bottom of a hill; it appears in that case the "internal speed" matches the speed limit. In other words this has the effect that minecarts sent down ramps of varying heights will still stop just short of 15 meters after the end of the slope.

'Note that as of the 1.2_01 update, certain boosters may not cause minecarts to travel as far. This can be fixed by placing a double booster.'

Loss of speed
One unit of kinetic energy could be defined as the energy gained by a cart going down a one block slope, and lost by a cart when it goes up a one block slope. If a 45 degree downward slope is connected directly into an upward slope, an initial height of 60 blocks will result in a final height of 40 blocks, a loss of 20 units of potential energy. But if 20 sections of flat track are inserted between the slopes, the final height will be 35. This implies that one unit of energy is lost for every 4 sections of horizontal track traveled with an initial stored energy of between 60 and 40. At much lower speeds, much less energy is lost, implying that the energy lost is a percentage of the cart's current energy. The above gives about 0.5% energy loss per section of track. One implication of this is that more energy lost when the cart has more energy, so a gradual slope should allow you to travel much farther distances than a steep slope followed by a long flat section.

Anything in the way of the minecart will take it to a dead stop, including: blocks, items, and mobs. Once a minecart has left the track, it will rapidly decelerate within one or two squares. It is possible to have a sufficiently boosted minecart "skip" over one square without a track, then rejoin the track at reduced energy later. When a mob touches a minecart they affect it in the same way a player would, i.e. mobs that move up against a still cart will set it in motion. When a minecart hits a mob, the mob will ride it.

Collision
Minecarts seems to have about the same size as a block; 1x1. Because of this, a ladder or door will prevent it from falling down a 1x1 hole. This can be utilized to make minecart dispensers, by stacking carts on top of each other and dispensing them with the help of a booster. A single cart dispenser using a door can also be made by using a ladder to block the cart from falling off the door.

Additionally, you can transport carts along 1 block wide water streams without the minecarts falling by placing ladders underneath. By alternating the ladders, items can still fall through. Because streams carry minecarts at a very slow rate, a trap can be made where anyone sitting in a cart will be suffocated in a block directly above the stream, and their items can be collected below.

Carts on minecart tracks will also ignore collision in certain situations. A cart traveling downhill or on a curve with a block placed in front of it will go through the block. If it is going fast enough, it can skip through one block and reattach to track on the other side, at significantly reduced speed.

Special Minecarts
There are currently two types of special minecarts:
 * Powered Minecart - A self-propelled minecart that is powered by fuel.
 * Storage Minecart - A minecart that can store items like a standard chest.

Detecting Minecarts


There are a few different ways to build a sensor that activates redstone circuitry when a minecart passes by.

One way is to replace a straight piece of track with a wood or stone pressure plate. With enough momentum, a minecart will slide over the plate and rejoin the track on the other side, losing a great deal of that momentum in the process. A booster is often placed alongside the track to push the minecart over the plate. If a stone plate is used, it will only be activated by minecarts with a rider inside. A wood plate will be activated by any minecart, empty or not.

To avoid the loss of momentum, a wood pressure plate can be placed on the inside corner of a track bend. A minecart going through the bend may or may not catch the corner of the plate as it goes by. The slower the minecart is moving, the more likely it will activate the plate. At maximum speed, the odds are about 50/50. This sort of "tunneling" is a common collision detection glitch that can be found in many different games.

By repeating the corner plate construction a few times in a "zig-zag" pattern, as pictured on the right, a much more reliable sensor can be built (in the author's experience, 100% reliable). Evenly spacing the plates virtually guarantees that at least one of them will align properly with the game clock and intersect the minecart's bounding box. With their outputs ORed together, the plates act as a single, reliable switch.

Unfortunately, stone pressure plates do not work at all in this configuration, at least not with humanoid riders. They might be activated by larger mobs like cows and sheep, but this has not been checked.

Minecart Trains


After Friday July 30's Minecart update, creating Minecart trains became a much simpler solution to transporting goods. To create a train, start with a fairly short length of straight track with an open ending on one side. Put a Powered Minecart on the side nearest the open end, and then add Storage Minecarts or ridable Minecarts along the rest of the track. Then, turn on your Powered Minecart. It will push the other Minecarts as if it were a Minecart Train. Placing an additional Powered Minecart on the other end will allow you to make a two-way train, as minecarts currently only push other carts, not pull.

Glitches

 * Prior to Alpha version 1.2.2, destroying a minecart while riding in said minecart would cause the player to fall through the block below the minecart. This could be used to make secret entrances into bases, though entry in this way caused the loss of half a heart due to a short moment of suffocation. (This bug was apparently fixed, but has since resurfaced in Beta version 1.1_02)
 * Saving and reloading while riding a minecart will leave you stuck in the ground, lowered by one y unit. If you are on a level section of track, jumping will get you out of it; if you are on a slope when this happens, you may be stuck in the ground, suffocating to death.  Beta 1.3_01
 * Detonating TNT in close proximity to a minecart, even when doing so with the TNT submerged in water (such as a cannon), will often cause the minecart to disintegrate into numerous dropped minecarts.
 * Minecarts can be set on fire, but the mob or player inside the minecart will not catch fire from a minecart. (Pictured)
 * If you are sitting in a boat, minecart, saddled pig or saddled pig in a minecart while entering or exiting the nether the game will crash.
 * If there is a saddled pig in a minecart in a two block high space and you get on it you will slowly suffocate to death and be able to see under the ground
 * Riding a saddled pig in a minecart creates a self propelling booster.
 * If you are riding a minecart through any opening only wide enough for the minecart to pass through, (1x1,) you will pass through as well, but take suffocation damage.
 * When placing a minecart on a track in SMP, touching the minecart at all will cause it to glitch, creating a solid, unmovable minecart, and a ghostly cart that seems to move freely. After a short while, the game will crash. (This issue has been fixed as of Nov 10, 2010 in Minecraft Alpha v1.2.2 and partially fixed in Minecraft Server 0.2.4. The Minecraft Server Update 0.2.5 seemed to give the ability to now destroy minecarts with any tool, although the minecart is not animated when being hit.)
 * 2 minecarts placed on the same circular track will run forever.