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The most secret ARDS plan; fighting to the end

In 1942 the Second World War was taking on a new, global element. December 1941 saw the attacks on Pearl Harbour that drew the Americans into frontline conflict, while units from Northern Ireland were engaged in Burma, North Africa, Leros, Sicily and Italy. It was written1John W. Blake, Northern Ireland in the Second World War soon after the war that “the Allies appeared to make little definite progress towards victory. Every advantage was offset, (and) every gain had its corresponding loss. (The) entry of Japan into the war (…) was in its immediate effect disastrous.”

January 1942 saw the first American troops arrive in Northern Ireland, increasing the numbers available for the defence of the Island. Secret plans codenamed MAGNET2National Archives WO 199/1203, MAGNET, Some points in connection with the relief of BTNI by US troops drawn up in 1942 saw command for the defence of Northern Ireland pass from the General Officer Commanding (GOC) British Troops Northern Ireland (BTNI) to the Commanding General USA Northern Ireland Force (NIF). This freed up a huge number of British troops to deploy across the world. MAGNET proposed that six British battalions (between 3,000 and 6,000 troops) would be required to aid the civil powers and a further US infantry division (around 10,000 troops), plus one regiment less a battalion, would be also required.

With events across the world seemingly deteriorating and more troops committed to the fight abroad, it is no wonder that military commanders appeared concerned about a new threat of invasion. The plans contained in this article, as preserved in the National Archives (TNA), were for a last-stand scenario if Ireland had fallen to Axis forces and all remaining fighting forces had been pushed back into a final stronghold. This stronghold was to be the Ards Pennisula, and the plan was known as the ARDS defence scheme.

This scheme has been drawn up to meet a most desperate situation and there is no intention to carry out any specific work on it at the present time.

Brigadier, General Staff, B.T.N.I. 3 September 1942

Defence of the Ards Peninsula

This document has been converted from an original copy of file S/124/4G held under WO 199/2935 in the National Archives at Kew. The once highly classified document was closed until 1972. While it appears there were no intentions to undertake the formal construction of any of the defensive works in 1942, this work was placed on one month’s notice if the threat of invasion developed. An interesting note was made attached to the document which encouraged the preparation of the defences through the course of unit training, remaining under the direction of NID. No references to the ARDS defence scheme were to be made during construction and primary importance to concealment from the ground and air was placed on all works at the time.

The plans were so highly classified copies could only be distributed by hand carried by Officers. Records indicate only 12 copies of this document were printed, with this copy being Number 1, issued to the Northern Ireland District (NID).

Map trace – ARDS defensive positions

A copy of the map trace that is held in file WO 199/2935. Overlaying this map onto a modern digital map gives us the location of the battalion areas and minefields.

1. Object

The object of preparing and occupying the ARDS Position is two-fold.

  1. In the event of greatly superior enemy forces driving back our forces in Northern Ireland on Belfast, this vital centre will be defended to the last by its local garrison, reinforced by as many field force troops as can be used to advantage in its defence. If it appears that Belfast cannot be held, then the Ards peninsula affords a strong position where a garrison can hold out until reinforcements from England enable a counter-offensive to be launched.
  2. The ARDS position provides a rallying point for troops not required for the defence of Belfast and for garrisons, such as the RAF Regiment if and when they have been withdrawn from their original tasks.

2. General Description of the Position

The Ards Peninsula is a narrow peninsula formed by the inlet known as Strangford Lough. It is 24 miles in length and its width varies from 3 to 7 miles.

The country is rolling and open, particularly in the northern part. There are certain dominating features with a large amount of dead ground between, Towards the Southern extremity, there are numerous streams.

Woods occur only where there are private parks. They are suitably placed, however, to form the anti-tank foundation for Positions 1 and 2.

The east coast is washed by the Irish Channel., The defence of the Ards Peninsula presupposes that this coast can be considered secure. It is open to Easterly winds which prevail about 70 days of the year. There is foggy weather about 10 days of the year.

Generally, the east coast consists of low, rocky shores skirted by sunk reefs and ledges, backed by low and undulating hills. There are stretches of sand and shingle along the coast where landings could be made in fine weather from suitable craft.

The rise of the tide is 13 feet Springs, 11 feet Neaps,

Strangford Lough, which washes the West coast of the peninsula, varies from 2 to 5 miles in width, is shallow, and studded with islands. At the head of the Lough, there are considerable mud flats which dry out at low tide. Navigation is difficult anywhere in Strangford Lough as there are numerous shoals. Landings from shallow draught craft could be affected in many localities at all states of the tide.

The mouth of the Lough consists of 5 miles of a narrow channel, 0.25 to 1.5 miles in width. The waters in this channel have very strong tides. The town of Portaferry, where there is a quay, is at the narrowest point. Although it would be possible to cross this channel at slack water by boat, bridging is out of the question owing to the strength of the tides. Thus, an enemy could land a force across this channel but would have considerable difficulty in maintaining it.

3. Air.

The fighter aerodromes of Ballyhalbert J6463 and Kirkistown J6358 are respectively 4 to 6.5 miles behind ARDS Position 2 (see para 6), and 2 to 3 miles from the Lough coast. They are therefore within both ARDS Positions and should be maintained as long as possible to enable fighter cover to be given. Should these aerodromes become neutralized by bombing or artillery fire, they will still be. be possible to give fighter cover to the Ards Peninsula from England or Scotland. The coast of England is 77 miles and the coast of Scotland is 24 miles from the Ards Peninsula. In this way also, when a counter-offensive is launched, fighter cover and bomber support from England and Scotland would be available both to support the counter-offensive and to bomb the enemy’s lines of communication and ports of disembarkation in Eire.

4. Line C

The positions on the Ards Peninsula follow logically after Line C Belfast – Scrabo Hill J4772 (at present in abeyance, but partially prepared). The holding of Line C fits in with the defence of Belfast and also with the holding of Ards Position 1.

Line C will be held so long as Belfast is holding out successfully, but if it appears certain that Belfast must fall, Line C will swing back Eastwards to become ARDS Position 1.

5. ARDS Position 1

An aerial view towards ARDS position 1 looking west, a defensive line connecting Grey Point (to the left) and Scrabo Hill (to the right)

This position extends from Grey Point J4583 to Scrabo Hill and thence along the Eastern coastline of the Lough including the channel. It follows the front edge of the Crawfordsburn J4681 and Clandeboye J4779 woods, thence West of Newtownards J4874 to Scrabo Hill. This position will be held provided there are sufficient troops to hold the line and effectively watch the coastline of Strangford Lough and the channel, If this is not possible, Position 2 should be occupied instead.

6. ARDS Position 2

An aerial view towards ARDS position 2 looking south, a defensive line connecting Ballywalter (to the left) and Grey Abbey (to the right)

This is the final position and must be capable of holding out for a protracted period. It extends from Ballywalter Park J6268 to Grey Abbey J5867, and thence along the eastern coastline of the Lough, including the channel which at this stage will require strong defences.

7. Method of holding positions

(a) The Lines – In both positions the line across the peninsula will be held by troops in all-round localities. It is essential for the line to be tank-proof, and where it is not naturally so, anti-tank mines will be used.

(b) The Channel – In both positions it will be necessary to, defend the North-West of the channel at the mouth of the Lough, A strongly defended locality will be necessary at Portaferry and patrols will watch the remains of the channel coast at slack water.

(c) The Lough coast – This is so extensive, particularly in Position 1, that it can only be defended by patrols and a mobile reserve. For these, all available light tanks and armoured fighting vehicles from aerodromes and aerodrome relief columns will be used, All search-light equipment that can be collected in the peninsula will be used at watching points along the Lough coast, anti-aircraft equipment, both heavy and light, will be used to cover the water, in conjunction with search-lights.

8. Troops available

These will include:

  1. Field force
  2. Young soldiers, Home Defence and Garrison battalions under N.I.D.
  3. R.A.F. Regiment garrisons and ground staff from aerodromes which have been evacuated.
  4. Home Guard, other than those holding out in centres of resistance.
  5. Anti-aircraft (A.A.) units and detachments with heavy and light A.A. equipment and searchlights.

Arrangements to warn units in (3) and (5) and transport them with their equipment to the ARDS Peninsula must be made in good time.

The number of troops required in Positions 1 and 2 to hold the line across the peninsula, furnish patrols and constitute an adequate reserve, is calculated in appendices “A’ and “B’ respectively.

9. Defence stores

The quantities of wiring stores, tools for digging and anti-tank mine required for the line across the peninsula in Positions 1 and 2 are given in Appendix “F.”

It will be necessary to dump these stores close to the lines in plenty of time. They must always be available and will be kept earmarked in depots in normal times.

10. Water

A plentiful supply of water is available, particularly in Position 2. Some purification may be necessary. Details are given in Appendix “C.”

11. Administration

Estimated reserves of supplies, ammunition and petrol and how they should be held or dumped are given in Appendix “D.”

12. Reinforcement and replenishment (ports and beaches)

Certain Ports and Beaches exist on the East coast of the peninsula. Details are given in Appendix “E.”

Appendix A – ARDS Position 1

1. Length

  1. Line – 7.5 miles.
  2. Coast of Lough – 22 miles.

2. Description of Line

This position extends from Crawfordsburn Wood to Scrabo Hill thence the east coast of Lough Strangford. It includes the belt of trees running south from Helens Bay, Bangor Reservoir and Newtownards but excludes Cairngaver (see trace attached as Appendix “F’ for battalion areas).

The ground is generally undulating with some dominating features.

The only anti-tank obstacles are woods, one small reservoir and the town of Newtownards.

Roads are numerous and will take tanks and motorised troops; and where the woods do not provide obstacles the ground off the roads is also suitable, especially between Cairngaver and Newtownards.

The main features in this line are:~

  • The high ground north of Bangor Reservoir which affords good observation and fields of fire,
  • Cairngaver however is difficult to hold and is a good artillery target.
  • Whitespots covers the line of advance from the south-west.
  • Scrabo Hill which covers the enemy’s line of advance and in enemy hands would overlook Newtownards and the aerodrome.

The position except in the north generally lacks cover from the air.

A coast road follows the east side of the Lough.

3. Troops required

  • To hold the line – ten battalions.
  • To patrol the coast road and prevent enemy landings from the Lough – two battalions.
  • As a reserve three to six battalions.

The total estimated requirements therefore to hold the ARDS Position 1 are one division and two brigades and, if possible, two divisions.

Appendix B – ARDS Position 2

1. Length

  1. Line – 3 miles.
  2. Coast of Lough – 16 miles.

2. Description of Line

This position extends from Ballywalter and Greyabbey. At each end of this line are the woods of Ballywalter Park and Rosemount which are good anti-tank obstacles. Between these two obstacles, there are 2,000 yards of open ground particularly suitable for tanks. Small hillocks are numerous, but there is no dominating feature.

The ground north and south of the position is similar.

3. Troops required

  • To hold the line – six battalions.
  • To patrol the coast road and prevent enemy landings and as a general reserve – three battalions.

The total estimated requirements therefore to hold the ARDS Position 2 are one division.

Appendices C and E – Water supply and landing beaches

Water supply

Water supply in the Ards Peninsula is generally unsatisfactory. The height of the land rarely exceeds 100 feet and there are few catchment areas.

Town with water supply capable of serving an increased population on a reduced gallons / head figure are marked in blue on the map below.

There are towns relying on wells for their water supply, from which the daily yield is insignificant; Millisle, Greyabbey, Kircubbin, Ballyhalbert and Portaferry. Potential water supplies are marked in green.

Ports and beaches

The East Coast is generally rocky, but certain beaches afford suitable landing places for both troops, vehicles and stores. The approach to the beaches is shallow, and in some places rocky; this will necessitate the use of special; shallow draught craft such as Tank Landing Craft, etc., or ship’s boats, for the final stage, entailing a passage of about one mile in these craft from the transports to the beaches.

There are four small ports which can accommodate vessels drawing not more than 10 to 12 feet; for details see below.

A strong tide race runs in the entrance to Strangford Lough and bridging is not considered possible.

Appendix F – Stores and equipment required

The below stores, not including tools, are covered by the usual stock and Royal Engineer Park Ballyclare, without affecting BTNI Operational Reserve. Tools are available only in BTNI Operational Reserve.

It is estimated that the initial stage of each position can be completed in 2 days, provided work is continuous throughout the night and day.

During two days, 700 men can lay a double belt of mines, five rows, and five yards apart.

The Royal Engineers are to be employed in:

  • Own local positions;
  • Construction of a defensive demolition zone;
  • Clearing field of fire and preparing buildings for defence.
EquipmentPosition APosition BSubsequent use
Dannert wire entanglement coils13,0147,277
Pickets screw long37,59620,8788,000
Pickets screw short17,600
Barbed wire, cwts (tons)362 (16.4)202 (9.2)396
Mines anti-tank12,5405,2808,500
Explosives with due proportion of accessories, lbs (kg)12,000 (5,443)12,000 (5,443)10,000
Points, camouflet100100
Sandbags, RP3Rot Proof100,00060,0001,600,00
Cement, cwts (tons)40 (1.8)30 (1.4)60 (2.8)
Chesnut paling, yards10,000
CGI4Corrugated Iron is used for revetting trenches and for roof shelters. It is used in sheets 6, 7 and 9 feet long by 2ft 2in wide, weighing respectively 16, 18 and 28 lb., XPM5Expanded Metal is used for revetting frames. It is made in sheets 6’6″ long by 3′ wide, weighing 8.5 lbs per sheet. It is usually issued in cases of 20 sheets., Nissen liners and other revetment as available, sheets3,000
Pit props, assorted4,000
Wire, 14 SWG, cwt (kg)22 (997)
Duckboards6Likely also known as trench boards. Used to give a firm footing in trenches. Weighing 35lb each.25,000
Nails, 4″, cwts22
Nails, 6″, cwts11
Hammers, claw200
Saws, hand100
Axes, hand200
Hammers, sledge48
Bill hooks200

I think it’s important to remember that most troops evacuating to the ARDS area will be bringing with them weapons, ammunition, tools and other equipment vital for the defence of the peninsula. There would have been armoured vehicles, tanks, artillery, mortars, heavy and light anti-aircraft guns and searchlights. While researching this article I have images of Dunkirk on my mind, but the reality of any evacuation to the Ards Peninsula would have been a pre-planned operation (as this document indicates it was).

Digging in

Scenario: Axis forces have landed in the south of Ireland, and met with little resistance. They quickly gained a foothold and gained control of a number of Irish ports. They have been landing equipment and troops in preparation for a push north and east, into Wales. The Royal Air Force is diminished and unable to provide adequate air support other than harassing bombing missions from airbases in England. The Royal Navy has been targeted heavily by u-boat wolfpacks, and the Axis forces have an almost unchallenged shipping corridor to the south of Ireland. United States forces have pushed south from their bases in Northern Ireland and are engaged in heavy fighting. They are supported by small numbers of fighters and medium bombers operating from forward landing grounds in the Irish Republic.

Forward seven weeks …

Allied forces have been pushed back into Northern Ireland. Heavy fighting is underway across the country and the enemy pushes towards the industrial capital of Belfast. The Commander British Troops Northern Ireland has activated the ARDS scheme.

The activation of the ARDS scheme had huge implications for the defence of Northern Ireland, it was almost a preemptive acknowledgement of defeat. As positions across the country fell or became untenable, troops would have been evacuating and regrouping on the Ards Peninsula. It seems logical that the Clandeboye Estate would have been requisitioned as the forward headquarters; it is a central location to regroup, and sits just behind ARDS position 1, with a large estate for the mustering of personnel and equipment. Before the construction of defences began, much of the engineering tools and equipment may have been moved forward to somewhere like Newtownards aerodrome, an existing military airfield with large areas to store equipment that is already well-defended. Air cover and fighter support would come from the airfields at Ballyhalbert and Kirkistown.

At this stage of fighting, the defenders would not be looking to construct fixed defences such as pillboxes. in fact by 1942 it was acknowledged by GHQ Home Forces7Memo: Subject;- construction of field defences, SECRET, 23 February 1942. Accessed from TNA, file WO 199/36 that “all experience of modern warfare since (May 1941) points most strongly to the fact that the pillbox is not a suitable type of fortification for (…) nodal point defences”.

These defences would be dug and constructed by the field forces (infantry). The Royal Engineers would be employed elsewhere, and the use of civilian construction workers would not be possible. Troops would be required to construct field defences using rudimentary tools (such as those depicted below). Be under no illusion, this is trench warfare.

Using my collection of contemporary training pamphlets and military manuals, I can get a real sense of what would be involved in constructing the ARDS defensive positions. We also have a good idea of the nature of the defences from the stores and equipment stockpiled for their construction.

The first stage of defence is to slow or stop the advance of the enemy. For this, obstacles were used. Where suitable, natural obstacles would have been used; such as rivers, thick woodland and even hedges to provide cover from view. Obstacles should be far enough from defended positions so as to be beyond the reach of the enemy force, but all obstacles must be under the cover of the defender’s weapons. Finally, concealment is key. All efforts should be made to conceal the presence of obstacles before the enemy arrives, nor should the obstacles give away the location of the defender’s positions.

Infantry obstacles

Quick to erect and efficient at delaying infantry soldiers, wire obstacles would have been common across the battlefield. The ARDS plan requested over 20,000 reels of Dannert concertina wire to cover both position 1 and position 2. It is a fair assumption that wire obstacles such as the example below would have been constructed across all vulnerable sections of the defensive lines.

Regardless of how well concealed a defensive position is, they were often betrayed by their wire obstacles. Concealment of wire in the open may be difficult to disguise, but efforts could be made to help it blend into the environment.

In the example image8Camouflage, Military Training Pamphlet No. 46, Part II, Field Defences, 1941, Plate II (left) there is a good example of a wire fence obstacle mirroring field boundaries and hedge lines. There would have been ample opportunity for this technique in the countryside of the Ards Peninsula.

Anti-tank obstacles

Given the urgency of the defensive construction, it’s highly unlikely that there would have been time to construct anti-tank defences such as ditches. There are a number of natural woods across the peninsula at both positions 1 and 2 (contributing to their selection as defensive positions). With a large number of anti-tank mines being stockpiled, anti-tank minefields were guaranteed to be deployed.

In the image to the right9Manual of Field Engineering, Volume II, 1936 there is a simple example of a minefield layout. Close spacing was utilised in locations of a roadblock, preventing vehicles from circumventing the road obstacle. The mines were spaced 1 yard apart, with a distance of 1 yard between rows. There would have been a minimum of 2 rows laid.

The open spacing pattern was more likely in the ARDS plan. Spaced in a 10×10-yard grid, belts of 100 yards or more would have been laid across large open areas of the countryside.

In the open spacing plan there would have been sufficient anti-tank mines to lay them 10 deep and 1,250 across (a span of 1,250 yards or 11.4 km). Measuring the minefields on the ARDS scheme plan, they stretched just over 5km, suggesting the minefield may have been up to 20 mines deep.

Field defences

With sufficient notice, and working day and night, troops could have developed robust defences. An example of these10Field Service Pocket Book, Part I, Pamphlet No. 7, Field Engineering, 1944 harks back to the trenches of the previous World War. The upper image (Fig. 14) shows a section post; a fighting position for 8 men which includes not only fire bays from which to shoot but a latrine, water tank and dry storage for ammunition and food.

The lower position (Fig. 15) is for a larger unit of platoon size; approximately 30 soldiers. This combines three section posts, connecting trenches, a communal cooking position and an HQ element. There is also a position for the platoon mortar.

The outposts marked on the map trace at the start of the article would likely have each looked like this.

Defensive buildings

One of the roles of the Royal Engineers was to prepare buildings for defence 11ARDS plan, Appendix F, para. 6. The above image12Field Service Pocket Book, Part I, Pamphlet No. 7, Field Engineering, 1944 shows what this would constitute. Strengthening the building, blocking entrances, stockpiling supplies and ammunition and elements of camouflage to hide the activities inside. These buildings would not have fought in isolation, having the support of infantry positions in the surrounding area or neighbouring houses.

How well-sited were the ARDS?

I think the easiest way to interpret the positions is by using an annotated map. Taking the same outline of positions included in the original file, I have added some notes about the terrain and how the positions could have been used to best effect.

Were any of the ARDS positions constructed?

A covering note on the ARDS defence plan stated that “there (was) no intention to carry out any specific work on it at the present time“. It did however go on to suggest that “if it is possible to carry out any preparation of the defences, including wiring, in the course of unit training, every opportunity of doing so will be taken“.

With this in mind, it is highly likely that defences were constructed in support of the ARDS scheme. With the added caveat that troops would not have been told that their training exercise was in fact contributing to a most secret defensive plan, it is unlikely that any earthworks would have been associated with this plan, perhaps dug and filled in at the end of the war.

There are a number of possible areas of the ARDS plan where digging may have begun and that may still preserve some evidence of this. These are primarily the main strategic areas of high ground around Cairn Wood / Cairngaver and Scrabo. The wooded areas around Helens Bay, Clandeboye and Whitespots also would have made ideal training locations where considerable field defences could have been constructed while retaining cover from air photography. The same applies for the lush woodland around Greyabbey and Ballywalter Park at either side of position 2. I think it’s unlikely that any wiring was undertaken in the open areas, and I am certain no mines would have been laid without the imminent threat of invasion.

Have you explored any of these woods and discovered what could be fire positions or trenches? Perhaps they are linked to the ARDS plan. Keep your eyes peeled and let’s all be thankful the scheme was never implemented.


You can download a copy of the original file and map overlay as contained in the National Archives file WO 199/2935.

  • 1
    John W. Blake, Northern Ireland in the Second World War
  • 2
    National Archives WO 199/1203, MAGNET, Some points in connection with the relief of BTNI by US troops
  • 3
    Rot Proof
  • 4
    Corrugated Iron is used for revetting trenches and for roof shelters. It is used in sheets 6, 7 and 9 feet long by 2ft 2in wide, weighing respectively 16, 18 and 28 lb.
  • 5
    Expanded Metal is used for revetting frames. It is made in sheets 6’6″ long by 3′ wide, weighing 8.5 lbs per sheet. It is usually issued in cases of 20 sheets.
  • 6
    Likely also known as trench boards. Used to give a firm footing in trenches. Weighing 35lb each.
  • 7
    Memo: Subject;- construction of field defences, SECRET, 23 February 1942. Accessed from TNA, file WO 199/36
  • 8
    Camouflage, Military Training Pamphlet No. 46, Part II, Field Defences, 1941, Plate II
  • 9
    Manual of Field Engineering, Volume II, 1936
  • 10
    Field Service Pocket Book, Part I, Pamphlet No. 7, Field Engineering, 1944
  • 11
    ARDS plan, Appendix F, para. 6
  • 12
    Field Service Pocket Book, Part I, Pamphlet No. 7, Field Engineering, 1944