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I--- Fortifications
 I---   ** Cape Wanbrow (Oamaru) **


141 Heavy Battery NZA OAMARU

Colchester type gun shelter, 141 Hvy Bty NZA The Cape Wanbrow Battery Observation Post The Cape Wanbrow Magazine

Coast Guard Cutters Chelan (Lake) Class
USCGC Shoshone Transfered 1941 as HMS Languard, Y-56 USCGC CAYUGA WPG163 Transfered 1941 as HMS Totland

Ten Lake Class cutters, all of which were transferred to Great Britain under Lend-Lease in 1941.
It was from the ships of this class that the New Zealand 5" Guns came

Fort Record Book
141 Heavy Battery NZA OAMARU

Gun: US Navy 5" gun 51 calibre MkVII 1912
No. 1506 (USN Gun Factory)
Ex USCG Chelan (Lake) Class Cutters
Mounting: Mk IX (1919) Fitted with tangent sights
Max Range: 16500 yds
Effective Range: 12000 yds
Gun crew: 13

Shell: 50 lbs   MV 2300fps
Time of flight: 38 seconds (Max range 12000 yds)
(From 5-inch Range Tables, Ordinance Pam No. 183 July 1922, Dept of the Navy)

Small Arms
LMG BREN MkI x2   (1 x tripod)
Pistol Revolver Webley No I Mk VI  x 1
Rifle .303 No I MIII* w/bayonets x 29
SAA Ammo
6800 rds .303 ball
18 rds .45 pistol

Infantry/Local Defence
1 Officer 19 0r's Home guard
(never implemented)
19th Independent Infantry Company ?

AA Defence
No AA defences
(BREN AA defence role)

Anti invasion & denial of the Port of Oamaru to the enemy
Secondary role: mine disposal

21 May 1942
Construction Commenced: 3 July 1942
Gun mounted: 30 July 1942
Manned: 27 July 1942 ( 1 Offr, 22 OR's)
Operational: 30 July 1942
Magazine, BOP & gun position completed and handed over by PW&D : 6 Nov 1942
Ammunition received: (5") 23 Dec 1942
Received Range finder: 3 Feb 1943
Reverted to care and Maintenance:13 Oct 1943

 NZ Archives CAWQ Ch540 3.14
Fort Record Book 85 Heavy Battery NZA Oamaru

The 5  5" Mark VII guns of this type were issued to the following Coast Defence Batteries at:


(Reproduced from the NZ Antique Arms Gazette June 1996)

by Rod Tempro

The history of Oamaru's Cape Wanbrow Coastal Defence Complex begins on December 7th, 1941 and the attack by the Japanese on Pearl Harbour.
First I will mention the connection with the gun and the ill-fated USS Arizona and second, the sudden threat of a Japanese attack on New Zealand which started a defence construction frenzy not seen since the Russian scare III the 1800s.

In June of1942, the Army authorised the construction of an emplacement with an I overhead cover for an American 5" naval gun. This was together with a magazine, a battery observation post and a military camp able to house the members of the gun crew and auxiliary troops.
The emplacement was of the familiar Gloucester type, with a rectangular block for the gun instead of the round block needed for the British 6". Costs were as follows:
Widening and metalling the road access 702 (completed in July 1942)
Plumbing, water supply and drainage work 1,802
Accommodation for 32 personal 8,328 (including mess, latrines, QM store, etc.) Total area:3,220sq.ft.
Emplacement completed: 28th July 1942. Overhead cover completed: 17th October. TOTAL COST: 17,568
The Army took over and moved into the camp in early November.

The gun was a US Naval 5", or 51 calibre No. 1506, made by the USN Gun factory  Mark VIII 1919 and was fitted with a MKIX mount for shore installation.
Maximum range: 16,500 yards. Arc of fire: 90. Sights: Mark XXl tangent sights.
The gun itself came via Pearl Harbour after being salvaged from one of the three Utah Class battleships which sank after the Japanese attack. The ships were the USS Arizona (sank upright and left as a war grave), the USS Oklahoma (turned upside down and sold for scrap in 1946), the USS Nevada (damaged and beached and returned to service in December 1942). All had twelve 5" guns as secondary armament. .!
This information came from Vice Admiral H. N. Wallin (Ret.) USN who, as a Captain in 1942 was in charge of salvage operations at Pearl Harbour.
"They were recovered by divers from the battleships after submergence in sea water ~ from December 7th to late May, 1942. The 14" guns from the main turrets were turned over to the army for ??? defence, the other guns were to be used in land lease agreements for friendly powers."

The gun was installed at Cape Wanbrow on the 30th July 1942. Its appearance, according to one of the men assigned to clean the gun, Mr Eric Fraser (formerly of Towey St, Oamaru) , was as follows:
"It had the appearance of having been immersed in sea water. By the time it went up to the Cape, it looked like a new gun."
The gun was in a good position at an elevation of approximately 200m above sea level, facing east, with a field of vision of over 180 degrees.
The gun fired three times. The first was on the 25th July 1943. Thus formed 141 Heavy Battery RNZA. Personnel were transferred from 80 Heavy Battery Godley Head and 81 Battery Eastern Point, under the command of 2/ Lieutenant L. A Watson. They were supplemented by men from 19th Independent Infantry Company, a local TF unit.

In August 1944, as a result of further reductions in coastal artillery, this Battery was handed over to Area 11.
On the 25th September 1944, the ammunition was removed and on 17th January 1945, the armament was shipped to Burnham.

The restoration of the above area is now into its fourth year. The Observation Post is now secured by a security fence, shutters have been made and installed, as have all interior doors. Restoration of the interior is now well under way now that it is vandal proof. The magazine, one of the earliest projects is now used as storage for all items we need to continue work. All the concrete foundations of various buildings have been cleared of undergrowth and a roadway bulldozed down to the old lighthouse area.

Acknowledgement: The Antique Arms Gazette, June 1996
& The Oamaru Coastal Defence Restoration Trust

Note: Peter Cook in his "Defending New Zealand, Part 1" states: -
"A popular perception had developed that the 5-inch guns had come from US Navy ships sunk at Pearl Harbour. The gun mounted at Oamaru, for example, was said to have been fitted to the Utah-class USS Arizona sunk by Japanese planes in December 1941. They were all received in a sorry state but not because they had been at the bottom of Pearl Harbour. In fact these guns came from the Royal Navy, which had received them on 10 ex-US Coastguard High Endurance Cutters of the Lake class. These had been transferred in 1940 under Lend Lease but soon disarmed and the guns put into storage. After five had been received in NZ, the barrels were scraped and painted. Mountings, however, took a bit more effort -that at Gisborne was unusable until it received a considerable overhaul.
Not forgoing what has been written above, the only information I can find relating to 5" guns and battleships and the Pearl harbour raids is a document in the Battery Log. It is the Gun Preparation, Firing and Maintenance Instructions for 5"/51 caliber guns and is from the Battleship, USSMaryland  BB46.
The USS Maryland survived the raids, she was inboard of the USS Oklahoma which was sunk. Damaged by two bomb hits she was repaired and re-entered service in 1942. It would appear that all her 5" guns were removed in this refit. Not all 5" guns on the USS Maryland were of 51 calibre, she also had 5"23 calibre anti aircraft guns. It is highly unlikely that these guns could made there way to New Zealand buy June 1942.
To put the matter to rest. A quote from Wikipedia.

"British service, Lend Lease US Navy 5/51 calibre gun
In World War II a small number of these guns entered British service on board ships transferred under the Lend-lease arrangement. Some of these guns were then transferred to New Zealand and deployed ashore for coast defense.""/51_caliber_gun

Inserted: July 2010

Status & Access:    Cape Wanbrow Gun Position is open to the public and maintained by the  The Oamaru Coastal Defence Restoration Trust
References:            NZ Archives CAWQ Ch540 3.14 Fort Record Book 85 Heavy Battery NZA Oamaru
The Antique Arms Gazette, June 1996

Coastal Defence Links

Godley Head
Fortress Area
Timaru Coastal
Mt Pleasant AA Battery Battery Point
Port Hills Defences Cape Wanbrow
Other WWII
Defence Installations
Miscellaneous Fortifications Pre WWII Defences


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Last modified: 06/18/10.