Why is it Called Plant Machinery?

Why do we call heavy machinery Plant?

What is Plant Machinery? Here, Plant Planet takes a look at what machinery counts as Plant and why we have such an unusual name for it.

It’s the type of question that crosses our minds during the quiet moments of our day before getting filed away in a mental drawer marked ‘clutter’ along side what was the best thing before sliced bread? and Do bees really have knees? It is, however, a question that has been long debated at Plant Planet HQ, and I’m sure we’re not alone.

But, Why Do We Call It Plant Machinery?

Heavy machinery comes in all sorts of shapes and sizes. With this machinery used for a wide array of earth-moving activities, the Heavy Machinery Industry is said to be worth £4 billion to the UK economy. While we know these facts, there seems to be no clear answer as to why we call Heavy Machinery ‘Plant’. The best theory we can give here is that the term was coined during a time that machinery used in construction, demolition, and other earth-moving activities, were predominantly static. If this is the case, the machinery may have resembled the stationary machinery used in factories – which can also be called plants (e.g Nuclear, Coking, and Steelworks Plants).


Another argument to support this theory is that the term ‘Plant’ used to describe heavy machinery and equipment is derived from the latin Plantus – ‘seed’ or ‘cutting’ – which was later influenced by the French Plantere, meaning ‘to fix in place’.

We can further note that, for accounting and financial purposes, Plant Machinery is considered a ‘fixed asset’. This is because the machinery is used consistently by a company to produce (or aid production of) a product. For example, Plant Machinery used on a construction site is actively used to produce the final product of a building.

However, this is only one theory as to why we might call heavy machinery ‘Plant’. Furthermore, the UK seems to be one of the only areas that uses the term Plant Machinery. Talk about your new Construction Plant Machine to an American or Italian and they may raise a quizzical brow.

But, What Counts As Plant Machinery?

Given the unclear origin of the term, it’s understandable that some debate has arisen around what exactly counts as Plant Machinery. As a result, there is grey area surrounding what some may consider plant, others consider heavy equipment, while others still consider tools or even property. Consequently, it might be helpful to look to a definition of Plant Machinery.

Unfortunately, we run into further problems here as no official definition of Plant Machinery exists. There are, however, some examples of popular interpretations of the term used widely in the industry. When it comes to legal or financial definitions, companies tend to look to the definition laid out in the 1887 taxation case Yarmouth V France:

 ‘whatever apparatus is used by a businessman for carrying on his business – not his stock in trade which he buys or makes for resale: but all goods and chattels, fixed or moveable, live or dead, which he keeps for permanent employment in the business’. 

Under this definition, all machinery used by a business to produce an end product would count as Plant. For example, all equipment used on a construction site from a 20 Tonne Excavator to a toolbox would count as Plant.

A simpler (and more industry relevant) definition might be that ‘Plant’ refers to machinery used in an industrial activity. By this definition, the Excavator would be considered Plant, but the toolbox and its contents would not. However, this definition is also up for debate.

Perhaps it might help to look at what machinery is likely to be classed as Plant by those working in Earth-moving Industries. Below are just some examples of machines that many class as Plant.

Really, It’s All Up For Debate.

So, there you have it. Despite numerous potential definitions, the reason that we call Heavy Machinery Plant remains a bit of a mystery.

Tell us why you think it’s called Plant over on Twitter.

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