Although no longer classified as Signalmen in the true sense of the word, the Signal Operators at Kwinana control a mini-network of lines into the many sidings of the industrial estates bordering the calm waters of Cockburn Sound. The area along this part of the Western Australian coast has long been established to support a wide variety of industries. Some of the traffic handled by the Kwinana cabin for these industries by Westrail are: Alumina, Bauxite, and Caustic traffic for Alcoa Australia; Coal for Western Power; Wheat for Co-Operative Bulk Handling (C.B.H.); Liquid Sodium Cyanide for Australian Gold Reagents (A.G.R.); Nickel for Western Mining Co. (W.M.C.); Sulphuric Acid for Fremantle Port Authority (F.P.A.); Steel for B.H.P.; Mineral Sands for Tiwest and general container traffic. For many years, Superphosphate was railed in both standard and narrow gauge trains, from the Cumming Smith British Petroleum (C.S.B.P.) works at Kwinana to many country centres, however this is now mostly handled by road transportation.

The Kwinana Cabin may look more like a very tall garden shed in the above view, rather than the important control centre that it is. The blinds are down not for privacy, but to ward against the hot, setting sun. The relay room is situated behind the cabin at ground level and has recently been expanded. At the time of this photo most of the points near the cabin were still worked by rodding. Now, some of them are power operated.

Presently, Kwinana works on both sides with Train Control now situated in the Westrail Centre at East Perth. Prior to Train Control, the signalling on both sides of Kwinana was contolled by the Signalmen at the Midland Signalling Centre - 'MIDSIG', adjacent to Westrail's Midland workshops (now also closed). The stations with which Kwinana worked on either side were: Wellard - a crossing loop to the east, and Cockburn South (part of the Cockburn triangle) from where a train could be sent to either Forrestfield or Robb Jetty. The original narrow gauge line to Robb Jetty serviced Naval Base, Clarence, Woodman's Point (Munitions sidings) and Coogee. This line was worked in the latter days by Train Staff & Ticket working (Staff only), and the line removed from a point just north of the Alcoa refinery and Woodman's Point when a massive floating oil-drilling platform was constructed near Woodman's Point.

The route-setting NX (eNtrance-eXit) panel is positioned above the 40 lever frame inside Kwinana Cabin. Prior to this panel, a smaller black-faced panel controlled a smaller area around Weston Street, now known as 'Bauxite Junction' No.8, the yellow lever at left, released the 'A' Frame while No.38 at right, controlled the switchlocked points into loco near 'A' Frame. Lever No.16 had the distinction of being a facing point lock on a slip-point!

Kwinana cabin houses a 40 lever McKenzie & Holland No. 9 pattern frame, which has, in addition to the normal McKenzie & Holland interlocking, has locally designed tappet locking applied at the very back of the lower tier of rocking shafts. In addition to the levers, a large NX panel is now situated above the levers. This panel has been added to many times since commissioning, and replaced a smaller, 'black' panel which was in use in the late 1970s. Lever No.8, coloured yellow, electrically released an enclosed ground frame called the Kwinana 'A' Frame, which was located at the Wellard end of the yard. During the 1990s, this frame was made redundant by alterations to the panel when the new locomotive depot was opened, and therefore Kwinana Cabin lost the official Box 'B' title, being named simply Kwinana. The semaphore Home signal at the Kwinana 'A' Frame has been moved to the preserved Claremont signal cabin. This signal will be re-configured as a co-acting signal - as it turned out, its original role - to represent the long vanished No.5 Starting Signal on the Up Main.

In spite of the complex nature of the work at Kwinana the cabin has only ever been rated as Second Class. Those who worked the cabin, often found it is akin to playing a gigantic chess game. Shunting, and other train movements required careful planning to prevent yard congestion, or conflict with other trains traversing the internal triangles or balloon loops in his area of control. The operators ability to co-ordinate this with the flow of traffic between the station either sides on only single lines, was, mostly unrecognised. The cabin should really have been rated First Class.

Kwinana's panel, looks fairly consistent in design, but behind the fascia, things are very different indeed. The slim, tall cabinet at the left of the panel houses sophisticated computer based electronics to control the extra tracks into the new locomotive depot. The re-signalling of the Wellard end of the yard saw the removal of the last motor operated semaphores in the state. The motors themselves, were first used on the three-position upper quadrant signals on the Eastern Railway which passed through Koojedda - so the 'eastern line connection' continued! Manual signals remain at the cabin - but they are not in the present Rule Book! Another anomally about the panel which is not at all obvious from the outside, is that the variety of magnetic 'memory joggers' cannot be used on the left hand half of the panel. This is due to that half, having an Aluminium backing, whereas the 'older' part of the panel (the right hand half) has steel backing plates.