"The Road Engines
( "Borrowing" The Clady / Creating a 'Head' )
The design of the Old Middle House mill was as efficient as possible and in the 1700s its power was enough to drive available machinery.
As industrialisation progressed, bigger machines with much bigger output required much more power.
Engineering ingenuity enabled much more power to be produced from the same river.
To do this it was essential to create a 'head" of water.
The Road Engines / Flax Visitor Centre is a cutely prepackaged example of this which, with very little effort, will allow visitors to see the principle at work for themselves.
Early water wheel schemes simply 'dipped' into the water, relying on the flow of the river to create power.
The amount of power depended entirely on the speed and amount of water in the river (flow).
Our very large Road Engines machines were driven using the extra power created by making a 'head'.
The red line on the left shows the "head".
The solid blue line shows the Clady River's normal downhill flow.
The dotted line shows how the water was taken from the river, held at almost a constant height along a 'mill race' and then dropped onto a wheel to create many times more power.
Linen on the Green assessed the Road Engines head at 19 feet.
This excerpt from the PRONI 2020 map identifies the main features of the Road Engines engineering works.
Every element in there, in the open, waiting for you to see.
Obviously great care needs to be taken when near water.
Boyne Row
Knockoneill River in its normal course
1. Road Engines intake sluice.
(Right beside Old Middle House & water wheel.
Road Engines Race maintaining water at the same height.
Road Engines mill house
(inc. Flax Visitor Centre)
System of stone arches to negotiate Kilrea Road.
Source: PRONI
Kilrea Road bridge