Here’s a note in the Powerscourt Guardian Minute books (#381) which indicates that the Forge Road was built in Summer 1849.
The new road from the corner of the Free houses on the Kilgarran Road to the Police Barracks in Enniskerry has been for some months completed and the agent now produces a letter from the assistant county surveyor stating that the whole expense of the deep cutting, filling up, forming, carting away marl &c &c and the building of a gullet &c amounts to £339.
Mr Maringay?, secretary to the Grand Jury (writing 23 Sept 1849) stating that Mr Sandys on the part of the late Lord Powerscourt promised to pay the difference between the total cost and the sum the Cess Payer agreed to paying: £100. Add to this the sum the Cess payer agreed to pay for a gullet (£15), the difference is £224.
The Agent requests an order from the Guardians to discharge – He would observe that the contractor William Williams, a very honest and industrious tenant on the estate, has fallen into arrears, and this sum will clear his rent up to last March and have a portion towards te September Gale. So that in fact, the Estate loses nothing by this transaction, as Williams has not chattels to any amount worth naming.
There is lots more on William Williams to come! The building of this road also led to compensation claims as many plots were cut into two small pieces or were destroyed by the steep bank left as a result of the new road.