Y Station, 16 Heavy Anti-Aircraft Battery

General

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Also known as

Mount St John Anti-Aircraft Battery; No. 2 Station, Gun Station 393

Classification

State Heritage

Register status

Entered

Date entered

26 November 1999

Type

Defence: Anti-aircraft defence

Theme

7.6 Maintaining order: Defending the country

Construction periods

1942, Mount St. John Anti Aircraft Battery - Magazines x4 (1942 February - 1942 April)

1942, Mount St. John Anti Aircraft Battery - Command Post (post-November 1942)

1942, Mount St. John Anti Aircraft Battery - Gun emplacements x 5 (1942 February - 1942 April)

Historical period

1939–1945 World War II

Location

Address

695 Ingham Road, Mount St John

LGA

Townsville City Council

Coordinates

-19.25652628, 146.74307442

Significance

Criterion AThe place is important in demonstrating the evolution or pattern of Queensland’s history.

Y Station, 16 Heavy Anti-Aircraft Battery (1942) is a representative example of Queensland’s anti-aircraft defences during World War II (WWII). In its location, layout and fabric, the Heavy Anti-Aircraft (HAA) position is important in demonstrating Townsville’s strategic importance and role during the war in the South West Pacific, when Queensland was the main staging area for the Allied defence effort.

Criterion CThe place has potential to yield information that will contribute to an understanding of Queensland’s history.

Y Station, 16 Heavy Anti-Aircraft Battery, has the potential to contribute knowledge that will lead to a greater understanding of the design, operation and site-specific modifications of HAA gun stations in Queensland. Areas around and between the built features may contain archaeological evidence, including communications infrastructure, command post pit features, and glass, metal and ceramic artefacts, deposited during the construction and brief but intensive occupation of the site.

Criterion DThe place is important in demonstrating the principal characteristics of a particular class of cultural places.

Y Station, 16 Heavy Anti-Aircraft Battery is an intact example of a HAA gun station built in Queensland during WWII. In its location, layout and fabric, it is important in demonstrating the principal characteristics of its type, retaining: a central semi-underground concrete command post with plotting room; a radiating arc of four concrete gun emplacements for 3.7 inch (94mm) anti-aircraft guns (with a visual relationship between the command post and the gun emplacements); four associated concrete magazines (one remains completely buried); and its siting in a strategic location to protect a facility from enemy air attack – at this place, on high ground overlooking Garbutt airfield to the east/northeast. A concrete platform for a Bofors light anti-aircraft (LAA) gun also remains.

History

Y Station (initially called No.2 Station, and later Gun Station 393) 16 Heavy Anti-Aircraft Battery, on Mount St John in Townsville, was constructed in early 1942 as part of the World War II (WWII) air defences of Townsville. Built to defend Garbutt airfield to the east/northeast, it retains: five anti-aircraft gun emplacements, a semi-underground command post, and four magazines. It is a representative example of the anti-aircraft defences of Queensland during WWII, and demonstrates Townsville’s strategic importance and role during the war in the South West Pacific. Since 2016 the place has been incorporated into the landscaped grounds of a private residence.

When WWII started in September 1939, Townsville, part of the traditional land of the Wulgurukaba and Bindal peoples, was an important Queensland port. Established in the mid-1860s, its subsequent growth was based on pastoralism, the sugar industry, and mining.[1]

Australia was under little threat of air attack until late 1941. On 8 December 1941, the United States of America (US) entered the war, following the previous day’s bombing of the American fleet at Pearl Harbour by Japanese carrier-borne aircraft. Simultaneously, Japanese forces launched assaults on Thailand, the Philippines and the British colony of Malaya. The sudden fall of Singapore on 15 February 1942 and the rapid Japanese advance through the islands of the Netherlands East Indies (NEI) raised fears of air attacks on Australia. The first Japanese air raid on Australia (Darwin) occurred on 19 February 1942; and Broome, in Western Australia, was attacked on 3 March 1942. Japanese air raids on other targets in Australia seemed likely, and an invasion of Australia was also feared.[2] America's General Douglas MacArthur arrived in Australia on 17 March, after being ordered to leave the Philippines.[3]

Due to its position in the north of Australia, Queensland was at risk of land-based air attack (launched from airfields in the NEI or New Guinea), as well as attacks launched from aircraft carriers. As a result of the growing fear of Japanese air raids, the Queensland Government issued the Protection of Persons and Property Order No.1, gazetted 23 December 1941, which ordered local authorities near the coast to build air raid shelters. All Queensland coastal state schools were closed in late January 1942, and although most reopened on 2 March 1942, student attendance was optional until the war ended. A policy of voluntary evacuation of women and children from Queensland coastal areas was also implemented on 27 January 1942.[4]  

After the raid on Darwin, many felt Townsville, the largest city in the north of Queensland, ‘would be the next to experience a large-scale raid…. However, due to its distance from the front line, it could not be raided by land-based bombers, which had added to the devastation in Darwin. Thus any [bombing] attack would come from aircraft carriers or long range Kawanishi flying boats’.[5]

Two key naval battles prevented carrier-borne Japanese aircraft being used to attack Townsville. The battle of the Coral Sea, fought 4-8 May 1942, resulted in the sinking of one Japanese light carrier, damage to a Japanese heavy carrier, and prevented a Japanese invasion force from reaching Port Moresby, New Guinea (now known as Papua New Guinea). The Battle of Midway, fought in early June 1942, resulted in the sinking of four Japanese heavy aircraft carriers.

Australia then became the springboard for the Allied attempt to push back Japanese forces. General MacArthur moved his General Headquarters, South West Pacific Area (GHQ, SWPA) from Melbourne to Brisbane on 20 July 1942, a day before the Japanese landed on the north coast of New Guinea in the Buna-Goa area and attempted to advance overland to Port Moresby, via the Kokoda Track. In September 1942, another Japanese landing force was defeated at Milne Bay, Japanese troops were halted at Imita Ridge on the Kokoda track, and a joint Australian-US effort to retake New Guinea began.[6]

Queensland played a major role in the build-up of troops and supplies for the counter-offensive. In late 1942 Townsville was the principal port for those Allied troops serving in the New Guinea campaign, and Cleveland Bay, between Magnetic Island and Townsville, was an important assembly point for shipping. The Australian forces chose Townsville as the Area Combined Headquarters for the North East Area, while the American forces used Townsville as the headquarters of the United States Army Base Section Two and the 4th Air Depot of the United States Army Air Force (USAAF).[7] Between 1942 and 1945 the Townsville and Charters Towers region became one of the largest concentrations of airfields, stores, ammunition depots and port operations in the South West Pacific Theatre.

Garbutt airfield, just west of Townsville, was defended by the Australian 16 Heavy Anti-Aircraft (16 HAA) Battery, stationed in Townsville early in the war in the South West Pacific. 16 HAA had two separate units defending Garbutt and its approaches: No.1 Station and No.2 Station. No.1 Station, at Jimmy’s Lookout, northeast of the airfield, was operational by 9 March 1942.[8]

Construction of No.2 Station (later called Y Station) at Mount St John, located directly west of Garbutt’s main north-south runway, commenced in February 1942 and was completed towards the end of April 1942; however, construction of its semi-underground command post did not commence until late 1942.[9] No.2 Station ‘was Townsville's largest and most modern anti-aircraft battery when completed… the site included ‘four concrete ammunition bunkers... four 3.7” [94mm] guns of the latest design, and an underground command post and plotting room’.[10] Four other 3.7 inch gun positions were built in Townsville: at Aitkenvale; The Strand; Pallarenda (3 Mile Creek), and south of the mouth of the Ross River. There was also a 3.7 inch gun station at Nelly Bay, Magnetic Island.[11]

Queensland’s static HAA gun stations typically consisted of a semi-underground command post, set to one side of a 180 degree arc of four octagonal gun emplacements, with about 100ft (30m) between the centres of the emplacements. Gun emplacements could either be built above-ground or set in-ground, and a gun crew usually consisted of 10-12 men. There were also two to four earth-covered reserve magazines (or shell stores), set outside the arc of gun emplacements. A typical command post included: an underground plotting room, entered from an external open pit which had separate compartments for a rangefinder, an aircraft spotter’s identification telescope, and a predictor. The predictor (a mechanical analog computer) was used to calculate where the aircraft would be when the shells arrived. It was manually programmed to follow a target, taking into account its course and speed, as well as the shells’ direction and velocity. This information was relayed automatically to the gun layers in each emplacement, so that all guns were trained on the same target area. The target’s height was deduced by the rangefinder, so that the fuses of each shell could be set to explode at the correct height. This targeting information, which was transmitted to dials on each gun, appears to have been relayed via underground cables, protected by metal conduits when above ground.[12]

At Mount St John, the 3.7 inch gun positions, which appear in wartime aerial photographs to have been originally surrounded by protective earth walls, consisted of an octagonal surface concrete platform, with a smaller hexagonal concrete mount and eight metal bolts fixing for the gun’s hexagonal metal base plate. There was also a concrete platform for a Bofors 40mm light anti-aircraft gun, just east of the command post. The command post appears in wartime aerials to have had an open pit with three connected compartments (or three separate pits) –likely for an identification telescope, rangefinder, and predictor – along its southeast side. Camp buildings and tents for the unit were located to the south, west and north of the arc of gun emplacements. The main access track to Mount St John during WWII came from Ingham Road to the south, branched both west and east around the hill, headed up to the gun emplacements, and down the other side of the hill, to the north. There were also secondary tracks heading east from the hill.[13]

No.2 Station's function was to observe all aircraft movements around Garbutt airfield and make sure that all aircraft followed the correct lane of entry. Any aircraft following an incorrect lane was to be fired on as an enemy aircraft. The Mount St John gun station was connected by phone to No. 3 Fighter Sector Headquarters (3FSHQ) at Townsville Grammar School [QHR 601029], as well as various other installations, and was staffed 24 hours a day. All four guns were in place by 11 March, and open sights were fitted on 22 March.[14]

At 1206 hours on 21 March 1942 the first Japanese aircraft was sighted over the city by observers at Kissing Point Battery. It was described in one report as ‘silvery underneath, wings like a Douglas, with the leading edge being tapered back’.[15]

The Kissing Point (coastal) Battery rang through to both No.1 and No.2 stations of 16 HAA; but discovered the phone lines were down. Even if either unit had spotted the aircraft, they would not have been able to fire accurately, as open sights were not fitted until the following day. Another unidentified aircraft was spotted on 22 March, also near midday.[16]

The names of the batteries were changed in April 1942, with No.1 Station changed to X Station at Rowe's Bay and No.2 Station to Y Station at Mount St John.[17] The first time both these stations fired on an enemy aircraft was on 1 May 1942. Intelligence recorded that: ‘At approximately 0945 hrs 16 A.A. Bty opened fire on enemy Recce aircraft flying at a great height. At approximately 1220 hrs U.S.A.A. Bty. opened fire on hostile aircraft, which made out to sea’.[18]

A more detailed description of what occurred on 1 May emerged from unit diaries: ‘Planes were sighted by X Station at Palleranda [sic] at a height of approximately 24,000 feet, heading directly towards the aerodrome at Garbutt. X Station immediately went into action and with the first salvo caused the planes to change direction and climb steeply to 29,000 feet and out of range of the guns. Y Station at Mt St John also went into action at this stage. In all, 33 rounds were fired; 25 from the station at Pallarenda and 8 from the station at Mount St John’.[19]

‘According to the unit diary, these two aircraft returned at 1140 hrs, releasing a balloon over Garbutt aerodrome at 25-30,000 feet. The balloon descended and blew out to sea, the diary remarking that "tactics proved that they were enemy aircraft"’.[20] The balloon was a radiosonde, or a dropsonde, which was an instrument platform with radio transmitting capabilities. It contained instruments capable of taking air temperature, humidity and pressure measurements at different heights. Its descent provided an indirect measure of wind speed and direction at various atmospheric heights. The data was then transmitted back to the aircraft. This information was vital for bombing accurately during a raid. ‘This was either a test run, or the preliminaries to a raid being planned… It is most likely that these flying boats were from the 14th Kokutai [Air Group] based in Rabaul harbour’.[21]

Mount St John's Y Station was involved in more action. Prior to Townsville's first air raid on the night of 25-26 July 1942, the city received a warning that a raid would soon occur. ‘This clue was unfortunately unheeded by military authorities. For three days prior to the first air raid on the city, AA [Anti-Aircraft] units were on high alert, with yellow alerts and unidentified aircraft reports occurring more frequently than usual. At 0920 hrs on 22 July 1942, unidentified aircraft were seen flying at 25,000 feet over Townsville. At 1000 hrs, Y Station at Mount St John reported "white balloon at 25,000 feet slowly descending". Once again the Japanese used dropsondes to record wind speed and direction at certain heights for a planned raid on Townsville’.[22]

Townsville was attacked three times during late July 1942, by the 2nd Group of 14 Kokutai Japanese Naval Air Force, using Kawanishi H8K (Emily) four-engine flying boats based at Rabaul. On the night of 25-26th July, two Emilys dropped bombs in the sea off Townsville's wharves. However, Y Station did not fire until a second raid early in the morning of 28 July. At 0220 hrs that day searchlights at Rowe's Bay picked up a lone Emily at 10,000 feet (3048m). After 20 rounds were fired from Y Station an explosion close to the nose of the aircraft occurred, causing it to drop its bomb load in an uninhabited area of nearby Many Peaks Range. During the third raid on the morning of 29 July 1942 an Emily dropped seven bombs in Cleveland Bay and one on a paddock at Oonoonba, and was intercepted and damaged by two US fighter aircraft.

By late 1942, Y Station was known as Gun Station 393.[23] During the war, at least 22 concrete 3.7 inch gun stations are known to have been constructed in Queensland for the Australian Army. As well as the six in Townsville, and one on Magnetic Island, six were constructed in Brisbane, and three in Cairns, as well as two at each military airfield at Mareeba, Iron Range (now Lockhart River Airport), and Horn Island. Two gun stations were also built at Jacky Jacky (now Northern Peninsula Airport), construction type unknown.[24]

By early 1944, when the fear of Japanese air attack had diminished, Townsville had 24 x 3.7 inch guns (in six gun stations); Brisbane was also defended by 24 such guns; and Cairns 12. In March 1944, a report to the Commonwealth’s Defence Committee recommended reducing the number of anti-aircraft guns in Cairns and Townsville, as they were now out of range of Japanese land-based bombers.[25] In early 1944, Volunteer Defence Corps (VDC) personnel formed complete ‘shadow units’, which could fully crew the guns. From mid-1944 onwards, the AA groups in Darwin, Cairns, Townsville, Brisbane, Newcastle, Port Kembla and Melbourne were disbanded.[26]

On 31 July 1944 the 16th HAA Battery was disbanded, and the guns were removed. Since the end of WWII, industrial development of the surrounding area has occurred, and parts of Mount St John were quarried, with soil being removed from near Y Station’s features, including most of the earth walls around the gun emplacements. Three of the concrete magazines were exposed, by earth removal during quarrying, to varying degrees by 1976. Sections of one gun platform and the stairs of two of the exposed magazines were also removed at some point. A wastewater treatment plant was built to the north of Mount St John, by 1976.[27] Y Station’s surviving concrete features remained on Mount St John in a ruinous, overgrown state. From 2016, these features were incorporated into the gardens of a large private residence, with landscaping including lawns, retaining walls, and new roads and footpaths. A section of the route of the wartime access track to the summit from the south has been reinstated for interpretation purposes.

Description

Y Station, 16 Heavy Anti-Aircraft Battery occupies the summit of Mount St John, located 2.3km directly west of the main north-south airfield runway at Garbutt, Townsville. The former gun station stands in the landscaped grounds of a private residence (2016, not of state-level cultural heritage significance) that in 2020 is bounded by the Mount St John Wastewater Treatment Plant to the north, undeveloped airfield land to the east, undeveloped land to the south, and industrial and commercial development to the west. The property is accessed via a private road that winds east from Toll Street.   

Features of Y Station, 16 Heavy Anti-Aircraft Battery of state-level cultural heritage significance are:

• Heavy Anti-Aircraft Gun Station (1942), including:
  • a command post
  • four Heavy Anti-Aircraft (HAA) gun emplacements
  • four magazines
• Light Anti-Aircraft (LAA) gun emplacement
• areas of archaeological potential
• location, layout and visual relationship of features within the place, including sightlines between the command post and gun emplacements
• views from the place, in a north to east arc, that demonstrate its visual relationship with and former role in protecting Garbutt airfield.

The HAA gun emplacements are in an arc configuration, radiating from the southwest to the north of the central command post, and the LAA gun emplacement is to the east. The surrounding magazines are to the northwest, southwest, east, and southeast.

Command Post

The command post is a reinforced concrete structure, formerly used as a central control point that identified and calculated aircraft trajectories, and distributed signals to the gun emplacements.

The command post comprises a semi-underground concrete-roofed plotting room, which is roughly square in plan. It is accessed via steps down to a doorway in the south corner and an escape hatch in the east corner of the roof.

The area southeast of the plotting room was the location of the former open pits (either three separate pits or one compartmentalised pit) – for an identification telescope, rangefinder, and predictor. Remnants include an exposed open-topped concrete box (assumed predictor cable terminus).

Partially exposed sections of metal conduits (assumed housing for signal cabling) are located to the southwest of the plotting room, and align with another open-topped concrete box (assumed junction box) embedded in a remnant earth revetment to the west.      

Features of the Command Post also of state-level cultural heritage significance are:

• remnant formed earth revetments
• concrete off-form walls and roof of semi-underground plotting room, with some visible formwork indentations
• two circular holes in roof of plotting room indicating location of former rotating metal ventilators (several detached ventilators are retained on site – including two adjacent to the southeast magazine)
• detached metal box (possible fuse box) on roof of plotting room
• main entrance to plotting room, including concrete steps, doorway with hinged metal door, and two metal posts to the exterior
• escape hatch to plotting room, including timber frame surround fixed to top with metal bolts, and hinged metal door with interior handle
• recesses to northeast and southwest walls of plotting room, with timber lining (northeast) and conduits linking to exterior
• concrete slab floor of plotting room
• exposed open-topped concrete box (assumed cable terminus) to the southeast of the plotting room
• embedded open-topped concrete box (assumed junction box)
• metal conduit, approximately 50mm in diameter: one connected to the southwest side of the plotting room; and one connected to the southwest side of the concrete box (assumed cable terminus) to the southeast; and five grouped together and partially exposed to the southwest of the plotting room and aligned with the concrete box (assumed junction box) to the west (further conduit and/or cables may survive underground, particularly between the junction box and each gun emplacement)

HAA Gun Emplacements

The four HAA gun emplacements are octagonal-shaped, concrete slabs of a standard layout, built to house and operate 3.7 inch (94mm) static anti-aircraft guns. They are located north, northwest, west, and southwest of the command post.

Each gun emplacement originally comprised a central unroofed gun pit, with a single entry point through an open side that faced the command post. The other seven sides likely had walls that retained the formed earth revetments. These features have been removed with the exception of a remnant earth revetment on the northern side of the southwest gun emplacement.

While no guns remain in place, their locations in the centre of the slab floors (excluding the north emplacement) are discernible through holdfasts (which would have attached to the hexagonal base plates of the guns’ static mounts).

Features of the HAA Gun Emplacements also of state-level cultural heritage significance are:

• concrete slab floors
• gun holdfasts set within the floor for hexagonal gun base plates, indicating the former locations of guns in the centre of each gun pit; comprising: eight metal bolts in a circular configuration
• circular pipe to the centre of the gun holdfasts, cut to the floor height

Magazines

The four magazines are reinforced concrete structures built to house ammunition for the gun station. They are rectangular in plan and located at a detached but accessible distance from the gun emplacements – to the northwest, southwest, east and southeast.

All magazines are of identical size, single-roomed and originally located underground with semi-concealed stairways, single metal doors and two metal ventilators on the roof. The southwest magazine is the most intact. The other magazines have had the soil around them removed and are in various degrees of exposure.

Features of the Magazines also of state-level cultural heritage significance are:

• remnant formed earth revetments
• concrete off-form walls and flat roofs, with some visible formwork indentations
• two circular holes in roof indicating location of former fixed metal ventilators
• metal ventilators
• semi-concealed entrance to southwest magazine, including concrete steps
• exposed concrete steps to northeast magazine
• single entrance doorways, with adjacent metal fixtures for doors (doors not extant)
• concrete slab floors

LAA Gun Emplacement

The LAA gun emplacement is an octagonal-shaped platform built to accommodate a Bofors 40mm mobile anti-aircraft gun. It comprises a concrete slab atop low, off-form, concrete walls, and is located on the downward slope east of the command post.

Features of the LAA Gun Emplacement also of state-level cultural heritage significance are:

• octagonal concrete slab
• low, off-form concrete walls.

Areas of archaeological potential

Areas where the brief but intensive occupation of the site has resulted in potential archaeological evidence that could contribute knowledge that will lead to a greater understanding of the design, operation and site-specific modifications of HAA gun stations in Queensland include:

• the area around and between the command post and gun emplacements. Potential archaeological evidence in this area includes underground communications infrastructure in the form of metal conduits and/or cables, particularly between the junction box and each gun emplacement. 
• the area around the southeast side of the command post plotting room. Potential archaeological evidence in this area includes underground communications infrastructure in the form of metal conduits and/or cables, and features, markings and artefacts that could indicate the layout of the open pit/pits that contained an identification telescope, rangefinder, and predictor.
• the remnant earth revetments adjacent to the command post, southwest HAA gun emplacement, and southwest, southeast and northeast magazines. Potential archaeological evidence in these areas includes metal, glass and ceramic artefacts associated with the construction and operation of the WWII gun station.

Features not of state-level cultural heritage significance

Features of the place not of state-level cultural heritage significance are:

• modern landscaping, including pool, concrete paths and steps, concrete block and stone retaining walls, lawn areas and plantings
• post-war graffiti.

References

[1] ‘Traditional owners’, https://www.townsville.qld.gov.au/about-townsville/history-and-heritage/townsville-history/traditional-landowners#:~:text=Traditional%20owners%20and%20custodians%2C%20the,lived%20in%20the%20Townsville%20region (accessed 29 October 2020); QHR 600937, ‘Townsville Custom’s House’; QHR 600906, ‘Townsville Railway Station and North Yards Workshop’; QHR 600916, ‘Tattersalls Hotel’.
[2] QHR 650230 ‘Heavy Anti-Aircraft Gun Station 385, Lytton’.  
[3] H Pearce, WWII-NQ: a cultural heritage overview of significant places in the defence of north Queensland during World War II, Brisbane, Environmental Protection Agency, January 2009, p.17.
[4] QHR 650230 ‘Heavy Anti-Aircraft Gun Station 385, Lytton’.
[5] R Holyoak, ‘The North Queensland Line: the defence of Townsville in 1942’, Thesis submitted November 1997 in partial fulfilment of the requirements for the Degree of Bachelor of Arts with Honours in the School of History and Politics at James Cook University, Townsville, 1997, p.16.
[6] Pearce, WWII-NQ, pp.16-19.
[7] Pearce, WWII-NQ, pp.47, 51, 61.
[8] Holyoak, ‘The North Queensland Line’, p.17; ‘Jimmy’s Lookout Anti-aircraft Gun & Search Light Battery’ Queensland WWII Historic Places, https://www.ww2places.qld.gov.au/place?id=1729 (accessed 6 October 2020).
[9] Holyoak, ‘The North Queensland Line’, p.17 (completion date) and p.100 (commencement date); National Archives of Australia, Series BP1/1, Allied Works Council - Queensland - minutes of meetings: Volume 3, Meeting 113, 11 November 1942, Minute 2555 (requisition for command post).
[10] Holyoak, ‘The North Queensland Line’, p.17. The 3.7 inch gun could fire a 28 pound [13kg] shell to a maximum altitude of 30,000ft (9 km), at 10-20 rounds per minute (Horner, The gunners, a history of Australian artillery, p.210; ‘QF 3.7-inch AA gun’, https://en.wikipedia.org/wiki/QF_3.7-inch_AA_gun (accessed 11 April 2019)).
[11] NAA, Series BP1/1, Allied Works Council - Queensland - minutes of meetings: Volume 2, Meeting 87, 5 October 1942, Minute 1686 (AA battery accommodation needed at Aitkenvale, The Strand, Jimmy’s Lookout, Mt St John, and Pallarenda); and Volume 5, Meeting 235, 10 May 1943, Minutes 6635 and 6636 (3.7 inch gun stations at Ross River and ‘Nellie Bay’); ‘Jimmy’s Lookout Anti-aircraft Gun & Search Light Battery’, Queensland WWII Historic Places, https://www.ww2places.qld.gov.au/place?id=1729 (accessed 6 October 2020); and

‘Three Mile Creek Anti Aircraft Battery’, Queensland WWII Historic Places, https://www.ww2places.qld.gov.au/place?id=1075 (accessed 6 October 2020). One 3.7 inch gun emplacement of the Magnetic Island gun station survives west of The Esplanade, Nelly Bay, between Kelly Street and Yates Street, in 2020; while ruins of the Ross River gun station are visible in the mangroves northeast of Ron Mclean Drive.
[12] Horner, The gunners, a history of Australian artillery, pp.209, 238; ‘6 (385th) Australian Heavy Anti-Aircraft (HAA) Battery’, https://www.ww2places.qld.gov.au/places/?id=2033 (accessed 25.3.2019). Some metal conduits survive, protruding from the ground just south of the command post, at Y Station The command post of Heavy Anti-Aircraft Gun Station 385, Lytton, also includes sections of four metal conduits, exiting a concrete compartment on the side of the concrete predictor pit (QHR 650230, ‘Heavy Anti-Aircraft Gun Station 385, Lytton’).
[13] Aerial photographs, October 1943, March and May 1944, courtesy of Ray Holyoak (show earth walls around the gun emplacements; pits beside the command post; and road/track formations on and around Mount St John). A hexagonal metal base plate, matching the layout of the bolts in the gun emplacements at Y Station, can be seen on an Australian-made 3.7 inch gun (1940), in AWM image 001595, ‘Finished product, 3.7 inch anti aircraft gun’, May 1940. A Bofors 40mm gun could fire a 2 pound (900g) shell, at 120 rounds per minute (Horner, The gunners, a history of Australian artillery, p.210).
[14] Holyoak, ‘The North Queensland Line’, p.17.
[15] Holyoak, ‘The North Queensland Line’, pp.32-3. The purpose of these reconnaissance missions was to locate airfields so a future strike could be arranged. It is possible that this particular aircraft was based in Lae or Salamaua (New Guinea), which had fallen on 8 March. US B17's operating out of Cloncurry, Charters Towers and Townsville had bombed both bases at least twice. The Japanese aircraft that fits the description is the Mitsubishi G3M3; a twin engine bomber/reconnaissance aircraft. Possessing a range of 3,871 miles, this aircraft was specifically designed for fast, long-range reconnaissance. It was the only twin-engine aircraft, which could make the distance from New Guinea, and was code-named Nell by the Allies later in 1942. It is shown on a pre-July aircraft recognition poster as the Type 96 Mitsubishi (Holyoak, ‘The North Queensland Line’, p.37).
[16] Holyoak, ‘The North Queensland Line’, pp.32, 33
[17] Holyoak, ‘The North Queensland Line’, p.17
[18] Holyoak, ‘The North Queensland Line’, p.44.
[19] Holyoak, ‘The North Queensland Line’, p.44.
[20] Holyoak, ‘The North Queensland Line’, p.44.
[21] Holyoak, ‘The North Queensland Line’, p.45. Rabaul is located today in the East New Britain province of Papua New Guinea.
[22] Holyoak, ‘The North Queensland Line’, pp.60-61.
[23] NAA, Series BP1/1, Allied Works Council - Queensland - minutes of meetings: Volume 3, Meeting 113, 11 November 1942, Minute 2555.
[24] QHR 650230 ‘Heavy Anti-Aircraft Gun Station 385, Lytton’. There were other HAA gun stations built: in Brisbane at Colmslie, East Brisbane, and Archerfield, and also at Amberley, but their construction type is unknown and they are not extant. Six of the gun stations at the northern airfields (at Horn Island, Iron Range, and Mareeba) are known to survive in 2020; the most intact being on Horn Island and at Iron Range. Two gun stations survive in Brisbane in 2020 (at Hemmant and Lytton); but none in Cairns.
[25] NAA, Series A5954, Item barcode 676482, ‘Coast and anti-aircraft defences. File No. 2’ (1944-48).
[26]  ‘6 Heavy Anti-Aircraft battery, 2/2nd HAA Regiment in Australia during WWII’, https://www.ozatwar.com/ausarmy/6haa.htm (accessed 3 April 2019); Horner, The Gunners, a history of Australian artillery, pp.391-395 (all static AA defences in Australia disbanded in November 1944, except in Sydney and Western Australia).
[27] DNRME aerial photographs QAP1085020, 5 December 1960, and QAP32248125, 20 June 1976.

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