In 1929 the line was operated under the Staff and Ticket Regulations. Train Advice 271 issued on 14 February 1929 (Chris Johnson Collection) describes the operating procedure during this period. Between Woburn and the Workshops all trains operated under the Staff & Ticket regulations. Staff & Ticket also applied to Race and Picnic trains between Workshops and Hutt Park. When the specials were not running the shunter could authorise operations between Workshops and the Waiwhetu Strean under One Engine in Steam Rules.

In 1937 the Industrial Line was operated as follows:

• No fixed signals at Woburn on the Industrial Line for trains arriving or departing from that station.
• No fixed signals at Hutt Workshops or Hutt park.
• Porter in Charge, Woburn, must not allow more than one train to be on the Branch at a time.
• Notice Boards define the Workshops and Hutt Park station limits.
• Three types of train could run, each at specified times of the day. The trains were shunting trains, special shunting trains to the Workshops and the passenger trains.
• The June 1937 WTT contained the following instruction: The occasions on which staff and ticket working will be in operation between Woburn - Hutt Workshops and Hutt Park will be notified, as required, by Train Advice.

Similar practices applied in 1947, including the instruction about staff and ticket working.

On 9 July 1956 Staff and Ticket working was removed from the 1943 Rule Book.

The inauguration of night trotting at Hutt Park on February 27th 1960 saw a resumption of special trains to Hutt Park, worked by EMUs. The EMUs were worked under Open Section Rules. From the 1920s to the 1940s race trains had been run with steam power.

S & I 917 (May 1961) indicates that opposite the northern entrance to the Workshops was a board which read Automatic Signalling Ends. Entering Open Section.

In the 1968 automatic signalling was installed. The signalling was completely removed by 1998, although it may have gone out of use earlier, following a fire at Woburn Station.

In 2001 part of the Branch was within Woburn station limits and part within Gracefield station limits (details below). Points at Woburn were hand wound.

After the Gracefield yard closed in 2002 the Stop boards were removed. I do not have specific information but from observation I suspect that the branch was operator controlled territory, with the Woburn Signalman (on duty as required) controlling movements at Woburn. Points at Woburn were hand wound. I believe that towards the end of this period an incident occurred in which two trains were on the branch. Subsequently an instruction requiring trains to contact Train Control before entering the branch was issued, but no boards were erected.

In 2006 three trains were allowed to operate on what was now called the Industrial Siding - Q4 Industrial Shunt; Q8 Workshops Shunt and Q9 Training Centre Shunt. Stop boards were erected and permission from Train Control was required before any of these trains could enter the siding. Only one train was permitted on the Gracefield Industrial Siding at one time. Elecrically locked switchstands at the north end of Woburn allowed train crews to operate the mainline points.

Comments on the diagram

• The diagram shows operations in July 2001.
• In 2001 the correct name of the branch is Gracefield Industrial Line.
• The "Hutt Workshops Stopping Place" is where the Workshops passenger trains stopped. These trains ceased running in the 1960s or 1970s.
• Following a fire in the Woburn station building several years ago most signals are either fixed red or blacked out. Running signals on the up and down mains operate automatically. Points 36, 39 and 41 are hand wound.
• Switchlocks are sill in place at Hutt workshops. The switchlocks act as mechanical locks now that fixed signals have been removed from the Branch. The switchlock nearest to Parkside Road has an electrical control to disable the alarms when the points are reversed.
• The Gracefield Industrial Line 0km peg is opposite the Woburn platform (beyond the right hand side of the diagram).
• The 242m between the two Stop Boards is an overlap.
• Signal 7 - Up Directing From Gracefield.
• Signal 69A - Shunt and Down Starting from Loop (Woburn).
• Signal 69C - Shunt and down starting from Sidings (Woburn).
• Signal 6 - Up Home from UIp Main (Woburn).
• In 1937 and 1947 Up was from Woburn to Gracefield.

Operating the Industrial Line in 2001

• Passenger trains do not run on the Industrial Line.
• The Signalman Woburn controls all movements between the Stop Board leaving Gracefield and No. 7 signal Woburn.
• The Gracefield Rail Operator/Remote Control Operator authorises all movements within the Gracefield yard.
• Up trains must obtain permission to pass the All Trains Stop Board before departing Gracefield to avoid being detained with the train fouling Hutt Park Road.
• Down trains must obtain permission to enter the Gracefield yard before departing Woburn. This ensures that the train will not foul Hutt Park Road.
• The signalman must obtain permission from Train Control before hand winding 36, 39 and 41 points. A white light on a shed adjacent to the points is normally on except when an up train is at or approaching 6 Up Home from Petone. The signalman's view of up trains is restricted by a curve south of Woburn.
• One train may operate between Woburn and the Stop sign and another in the Gracefield yard. Only one movement at a time may operate between the Woburn Station Limits and and 69A or 69C signals at Woburn.

I do not have any details of how the branch was operated between 2002, when the Gracefield Yard was closed, and August 2006 when signalling changes were commissioned at Woburn. Based on observation and rumour here is how I think that the line was operated:

• The Taita Signalman or the Workshops shunter acted as Signalman Woburn.
• The Woburn Signalman authorised trains from the Branch to pass signal 7 at Stop and enter the Woburn Yard.
• Procedures for handwinding 36, 39 and 41 points, to allow train to move to and from the main line, were similar to those described above for 2001.
• The Branch was operator controlled territory. This raised the possibility of more than one train being on the branch at the same time (say the shunt and a test train).

In 2006 trains enter and leave the mainline at the north end of Woburn, renamed Woburn North Siding. Train crews operate the electrically locked switchstands so a signalman is no longer required to be in attendance. 36 and 39 points at the south end of Woburn are security locked and are used only to reverse EMUs when there is a Block Of Line north of Waterloo.