Railway Signal Boxes

At the International Exhibition in Sydney in 1880, Railway Commissioner Herbert saw a display by McKenzie and Holland of “interlocking” machines which could be used to prevent conflicting train movements when points and signals were controlled from a centralised cabin. Interlocking of signals and points was a major factor in ensuring rail safety at busy stations by preventing conflicting movements likely to cause accidents. Most mechanical interlocking has now been replaced by electrical interlocking. This system could prevent accidents and also reduce the number of pointsmen required. The New South Wales Government bought the equipment on display, using it for the first installation in Australia. Queensland ordered the same equipment which arrived in October 1881. The first two installations were Roma Street, and Ipswich. Roma Street A contract was let for a signal cabin, which was eventually replaced The interlocking was completed in late 1883. The original signal cabin was replaced by a new elevated cabin in 1895, built by W. Chaplain. Queensland also ordered equipment for Brisbane and Ipswich. Roma Street was interlocked in 1882 and Ipswich followed in 1883. Although Ipswich was the second station in Queensland to have mechanical interlocking installed, it retained it long after it was withdrawn from Roma Street.

As part of the station yard alterations in 1921 a new 60 foot turntable was provided in 1921 near the elevated signal cabin, replacing the old 41 foot turntable which was too short for new locomotives.


The elevated signal cabin at Ipswich was built by W. Chaplain, the contract being signed in August 1895. The cabin accommodated a 55-lever T-Bar machine by MacKenzie and Holland Brisbane. This is the second largest T-Bar machine used in Queensland, after Baddow (56 levers) and was the largest surviving post 2000. It controlled train movements between Thomas Street and East Ipswich stations, and to the Railway Workshops across the river.

This technology has now become obsolete throughout Queensland. The Ipswich cabin was taken out of use in 1995.

As part of the station yard alterations in 1921 a new 60 foot turntable was provided in 1921 near the elevated signal cabin, replacing the old 41 foot turntable which was too short for new locomotives. Diesel electric locomotives generally were operated in both directions without turning. With the withdrawal of steam locomotives the majority of turntables and forklines (turning triangles) have been removed. The turntable was in frequent use especially in steam days, and also by diesel electric locomotives for trains which terminated at Ipswich.


The turntable at Ipswich was provided in 1921, replacing an earlier 41ft turntable. The turntable is still used as part of QR operations, mainly for the turning of steam locomotives.