Also known as two wheeled dolly or sack truck, the hand truck is an invaluable piece of equipment. Widely used in store rooms and warehouses, they are sometimes also used to transport baggage at train stations and other similar environments. Hand trucks are now available in some variety, some can even be used when going up or down flights of stairs, but they are all based around the same basic design.

The hand truck operates using the concept of leverage. Levers operate by multiplying mechanical force from one end – the ‘effort' (in this case the person pushing the truck), so that it can be applied with more force to another object – the ‘load' (boxes being pushed). In a basic sense a lever is a rigid object that is used with an appropriately placed pivot or fulcrum in order to achieve this increase in force. There are three basic classes of levers, the hand truck is a first class lever – the pivot is located between input effort and output load, the lever swings about the pivot when force is applied in order to overcome the force of resistance on the opposite side. Other examples of first class levers include see-saws, trebuchets and even shoehorns. In hand trucks the axis is the fulcrum, they are also designed to put the weight burden primarily on the wheels when in use, rather than on the user. One of the first to understand that simple machines do not create energy, they just transform it, was Galileo Galilei, he noted this is in Le Maccanicle in around 1600. With new understanding of these concepts from great minds of the scientific revolution, basic machinery was able to evolve. Levers are still considered one the six simple machines, alongside wheels and axles, pulleys, inclined planes, wedges and screws.

Of course the idea of levers had been around long before Galileo. Archimedes of Syracuse (c.287BC – c.212BC) is said to have had a great understanding of and belief in the lever. In a letter to King Heiro he is claimed to have said, that given a place to stand and a lever, he would be able to move the whole world. Although it has since been discovered that moving the earth with a lever would require mind boggling distances and amounts of time, Archimedes was able to demonstrate the power of levers in another way. He is said to have created the appropriate lever to launch a ship from a harbour by himself.

This may all seemed far removed from hand trucks and similar material handling products. They are tools used every day by companies and other organizations throughout the world, but the physics that explains how they work is rarely considered. It is worthwhile to remember that even primitive tools had to evolve and be understood before any serious technological or mechanical advancement could be made. The hand truck is an example of a basic lever that is still widely used today. It is also advantageous in that it is environmentally friendly, simple to use and durable. They can be cheaper to maintain than some pieces of equipment as they have fewer moving parts that can potentially need replacing. With several kinds available for differing needs, hand trucks are likely to be in use for a while to come.