Editing Compactor (section)

==Construction industry==
In [[construction]], there are three main types of compactor: the plate, the rammer, and the [[road roller]]. The roller type compactors are used for compacting [[crusher|crushed]] rock as the base layer underneath concrete or stone foundations or slabs. The plate compactor, vibrating plate, or tamper, has a large [[vibrator (mechanical)|vibrating]] baseplate and is suited for creating a level grade, while the rammer compactor has a smaller foot. The rammer, or trench rammer, is mainly used to compact the backfill in narrow [[trench]]es for water or gas supply pipes etc. Road rollers may also have vibrating rollers.

In plates and rollers, the vibration is provided by rapidly rotating eccentric masses. In smaller plates, the vibration causes a tendency to move forwards, while some larger plates are provided with a directional control. In the rammer the foot is mounted on a sleeve that slides vertically in the leg. Inside the sleeve, a piston is driven up and down by the engine through a reduction gear, crank and connecting rod. Substantial coil springs above and below the piston connect it to the sliding sleeve. The connection between the sleeve and foot is at a small angle so that the whole rammer leans away from the operator. The vibrating motion is therefore slightly off the vertical, and this gives the rammer a tendency to 'walk' forwards. The sliding joint in the leg is protected by a flexible bellows.          

In England the name "wacker plate" or just "wacker" is commonly used to refer to plate compactors, derived from the name of [[Wacker Neuson]], a well-known manufacturer of such devices. The name is pronounced in the English style as ''whacker,'' as opposed to the correct German ''vacker''. A rammer is colloquially referred to as "[[Irish people|Paddy]]'s Motorbike", due to the traditional resource of Irish construction labourers, and the way that the operator appears to "ride" the hammer holding the handles like a motorcycle.{{Citation needed|date=November 2009}}

<gallery mode="packed">
File:Plate compactor.jpg|A small plate compactor
File:Zageszczarka plytowa 2.JPG|A rammer compactor
File:2008-08-28 Wacker RT trench roller.jpg|A trench roller operated by remote control for operator safety
File:Seabees compactor roller.jpg|Large roller "sheepsfoot" compactor for use on soil
</gallery>