21st Construction Regiment ( Australia ) The 21st Construction Regiment ( 21 CR ) is a construction engineer regiment of the Australian Army Reserve . Part of the 5th Brigade , the regiment was formed in 1950 and is based in New South Wales where it provides support to the 2nd Division . The regiment has recently contributed personnel to a number of operations including the Regional Assistance Mission to the Solomon Islands , Operation Slipper and Operation Astute . It also regularly supports the Army Aboriginal Community Assistance Program and provides assistance to the Australian community in times of natural disaster . History . The 21st Construction Regiment was raised on 29 August 1950 in New South Wales through the " supplementary reserve " scheme that used the resources of various government departments , including personnel , to raise a reserve military capability within the Citizens Military Force . The regiment ' s first commanding officer was Lieutenant Colonel Douglas White , a World War II veteran , and upon formation the regiment consisted of the 101st , 102nd and 103rd Construction Squadrons and the 108th Plant Squadron . The following year the 109th Construction Squadron was raised as an independent squadron administered by the regiment . At the regiment ' s first annual camp in 1951 , a total of 29 officers and 163 other ranks paraded . In 1952 , the regiment was subordinated to the 5th Engineer Group , which was headquartered at Victoria Barracks in Sydney . A small number of regular personnel were detached to the regiment to provide training support . In 1958 , the regimental headquarters was established at Haberfield , New South Wales . Throughout the 1950s and 60s , the regiment undertook various construction tasks around the country , moving between Middle Head and Singleton . Annual camps took place at Middle Head , North Head , Glenfield , Ingleburn , Holsworthy and Singleton . In 1968 , the regiment was placed under the command of 11 CE Works when the 5th Engineer Group disbanded . In 1972 , the 109th Construction Squadron was redesignated 201 Work Section when its sponsor organisation , the Snowy Mountain Hydro Electric Scheme , was completed . The regiment returned to the 5th Engineer Group in 1975 . That year the regiment deployed over 350 personnel to Darwin to clean up the city in the wake of Cyclone Tracy . Two years later , further change occurred when 201 Works Section was redesignated 4 Troop , underneath the 5th Field Squadron , which was part of the 4th Field Engineer Regiment . This lasted until early 1980 when the subunit returned to the 21st Construction Regiment and once again became 201 Works Section . In 1987 , the regiment was placed under the command of the 2nd Divisional Engineers . Later that year , the 103rd and 108th Plant Squadrons were disbanded and reformed as the 26th Divisional Engineer Support Squadron . Throughout the 1980s exercises were undertaken in the Holsworthy and Singleton areas ; a major bridging project was also completed at Gladesville in Sydney with the support of the regular 17th Construction Squadron . Up until the 1990s when a centralised training model was adopted , the regiment undertook its own basic , employment and promotion courses . When the regiment had originally been raised under the supplementary reserve scheme , its personnel had been placed under conditions of service that enabled them to serve with only limited impact upon their civilian careers . This was done by allowing members only to parade for one annual two week camp a year . These conditions remained until 1995 when its personnel became subject to the same requirements of other Reserve units , which essentially required members to attend weekly parades and monthly exercises . In 1996 , the regiment was issued with a Unit Colour Patch that consisted of the purple background of the engineers and a red triangle . Throughout the 1990s , annual camps were undertaken in Rylestone , Shoalwater Bay , Holsworthy , Singleton , Port Wakefield , Goat Island , Majura , and Kapooka . The regiment has been heavily deployed since the beginning of the 21st century , with personnel being deployed on operations as part of the Regional Assistance Mission to the Solomon Islands , Operation Slipper and Operation Astute in East Timor . The unit has also contributed personnel to exercises in Papua New Guinea , Rifle Company Butterworth , and the Army Aboriginal Community Assistance Program . Based at Holsworthy Barracks , it is currently part of the 2nd Division ' s 5th Brigade , providing " construction engineering , hydro - graphic survey and Civil - Military Cooperation " capabilities . In 2011 , the regiment had a posted strength of 240 personnel and it consisted of Regimental Headquarters , 101 and 102 Construction Squadrons , Littoral and Riverine Survey Squadron and CIMIC Squadron . Commanding officers . The following officers fulfilled the role of the regiment ' s commanding officer :