No4 WMU was formed at Flemington Racecourse, Ascot vale, Melbourne, Victoria in early June 1942.

Squadron Leader R H Hoddinott was Commanding Officer and members were posted in from all states of Australia, as well as several AC1's from Recruit Depot, Shepparton, and Victoria. They were hand picked by the CO as they finished their rookie training.

The first detachment to be sent away was No 1 Section under Pilot Officer W E Derbyshire, with 25 personnel and equipment to New Guinea (This was the first RAAF Works Unit at Port Moresby), via Sydney NSW, in early July 1942, by rail, taking 3 days. Route was through Tocumwal and members and equipment were transferred to the NSW rail system, owing to change in railway track gauge. Arrived Sydney approx 6th July and billeted at No 2 Embarkation Depot (Bradfield Park), pending transport by ship.

Left Sydney 13th July 1942 per Netherlands/Dutch merchant ship "BOTH", which transported both troops and materials, (grouped with Aust Army Service Corp.) in a convoy escorted by two RAN corvettes.

Arrived Port Moresby 26th July and stationed at RAAF Headquarters, Konedobu, awaiting campsite to be arranged at Johns Gully (now Wards Strip) approx 9 miles from Port Moresby.

After a short time a camp was set up. Preparation of meals and cooking was in the open with a small wood stove/oven; messing was under a canvas tent fly. Permanent buildings such as cookhouse, mess building, orderly room (prefabricated), recreation building (grass) followed. Sleeping and camp arrangements were in Australian type tents. Water was obtained from the Laloki River main pipeline which supplied Port Moresby, rations from the Aust. Army Service Corp. Medical attention was at RAAF Port Moresby and 4 Fighter Sector (local).

First work undertaken was making serviceable an old building to be used as RAAF Postal Unit. Felling and lopping tall saplings from forest to be used as ridge poles in the building of grass shelters at airfield for aircrews, selecting sites for new camps, water location, camouflaging, digging slit trenches as well as many other small projects. These works were done in conjunction with RAAF Barracks Store, Port Moresby. A saw bench was erected from saw spindle, collars, and bearings, which proved very suitable. To cut sawn timber from rough timber origin the circular saw was driven by belt from a tractor.

P/O Derbyshire returned to the mainland after a few months with No 1 Section and was replaced by P/O Delfendahl.

In October, owing to buildings and campsites being urgently needed, extra personnel with F/O N. Mau in charge were sent from Townsville to increase the detachment, bringing the number to approx 60 airmen.

A telephone was installed at the Orderly Room and a motorcycle added to the equipment, which made communication much easier. No.4 W M U Headquarters brought with them heavy machines for earthworks, trucks, equipment, and stores and were quickly established. A generator for electricity was installed and made living conditions much more comfortable.

Detachments were also at Goodenough and Kiriwina Islands.

Officers and men were interchanged between detachments and Headquarters.

Officers with the Unit were (See attached Appendix)

Squadron Leader Murphy replaced S/L Hoddinott who had been Commanding Officer since the formation of No 4 WMU in June 1942. (Also was 1914 1918 WW1 Aust Flying Corps, Works And Building Inspector, RAAF Station Port Moresby (early 1942), Works Training Unit 1943 and 62 Works Wing 1944)

Many and varied work projects were carried out by 4 MWU (camp sites, eating and stores buildings, hangar type structures, kitchens, latrines and ablutions, alterations to existing buildings, prefabricated dormitories, earth works, recreation buildings (for meetings concerts etc), saw milling (from timber obtained in forest), etc.)

Airmen and officers were encouraged to participate in sporting activities and entertainment during stand down periods. The unit always had excellent competitions. A Sports ground, Boxing ring and Basketball court were constructed and used by many groups   Army, Air force (Australian and American) and others.

In November 1943 many of the original members of No 4 WMU, having had 16 months operational duty were posted to No 5 Mobile works Squadron (later No 5 Airfield Construction Squadron) to be granted Christmas leave in their home State on the mainland.

Victorian personnel were sent to No 1 Embarkation Depot (Melbourne Cricket Ground) as transit headquarters and in January 1944 re assembled to have extra training and then returned to the operational theatre in South West Pacific Area.

Those officers and airmen not being required for a second tour were posted to units in Australia.

On return to SWPA, 5MWS (No1 ACS) commanded by F/Lt Edwards were at Aitape landing on 25th April 1944 with reinforcements for 62 Works Wing. A 4 WMU detachment was also at this landing.

A forward detachment of 4 WMU arrived at ten with 62 Works Wing on 23rd June 1944, at staging camp prior to Noemfoor landing.

Late in 1945, No 5 ACS was sent to Japan and became a unit of the occupation force.

In 1946, as associations were being formed after the 1939 1945 War years several former members of 4 WMU having served with 5 MWS (5 ACS) became members of both groups.
No.4 Works Maintenance Unit was formed at Ascot Vale on the 9th June 1942. We find it located on 11th August 1942 at Townsville and detachments located at Bohle River, Garbutt, Port Moresby, Aitkenvale, Home Island, and Guerney (Milne Bay). These detachments were concerned with the general maintenance of strips and the erection of camp facilities for various squadrons and the maintenance of it.

One work party while working on Berry Strip experienced a heavy air attack from some 40 Japanese bombers, which severely damaged buildings etc in the vicinity. About this time also, detachments were operating at Goodenough Island, Kiriwina, Guerney, Nadzab, as well as Berry Strip (Work Party).

Squadron Headquarters was trans shipped from Port Moresby to Goodenough Island at the end of November 1943. On the 15th July 1944, the Squadron became known as No 4 Airfield Construction Squadron. In September 1944, the Squadron moved forward again to Noemfoor Island where work was commenced on Kornasoren and Kamiri Strips. In quick succession the Squadron moved forward again in January 1945, to Biak Island, Morotai, and Labuan where preparations were in progress for Oboe 6 when peace was declared.

The Squadron was disbanded in November 1945.

Commanding Officers
Flt Lt R H Hoddinott15/6/42   2/7/43
Sqn Ldr F W Murphy4/7/43   22/5/44
Sqn Ldr G W Barlow26/5/44   28/3/45
Sqn Ldr H B Trench28/3/45   Nov 45
No.4.ACS              (Previous 4W.M.U.
Formed        Ascot Yale      08.06.42
Moved         Townsville      11.08.42
Embarked    Townsville      10.02.43
Disembarked       Post Moresby 14.02.43
Moved          Goodenough         29.11.43
Moved          Noemfoor      19.08.44
Moved          Biak               08.01.45
Moved          Morotai          13.05.45
Moved          Labuan          10.06.45

The Squadron was disbanded in November 1945.

Detachments =

Port Moresby             06.07.42         14.02.43
Horn Island                05.09.42         14.02.43
Milne Bay                  19.11.42         15.09.44
Goodenough             20.05.43          04.07.43
Kiriwina                    03.08.43          15.09.44
Nadzab                     29.11.43          15.09.44