Decoding the IRA

by Tom Mahon

  Another security feature was that all documents had a unique identifier. For instance, letters from the OC in Britain carried the letters ‘HS’ followed by the number of the despatch in sequence. Thus, if Twomey received HS 10 and the next letter from Britain was HS 12, he’d know that a despatch was either delayed or possibly captured. This would allow the IRA to consider that the contents and the method of transport may have been compromised. Frank Kerlin explained this in a letter, ‘Dw 99 – Despatch 1’, which he had smuggled into Mountjoy prison for Donal O’Donoghue: ‘The despatch number on this despatch will be used in sequence in all despatches sent to you, to enable you to know if all despatches sent are received.’ Kerlin told him to acknowledge this despatch by way of a cryptic question to one of his visitors: ‘When you receive this despatch, ask Mary Mc or Kathleen how their sister Madge is.’21 More commonly the recipient was expected to acknowledge each letter in writing. And O’Donoghue wrote to Kerlin: ‘[I] wrote last week [and] received no reply. Always acknowledge [my letters] otherwise [I’m] uneasy.’22

  Like any other organisation, the IRA needed ready access to its files to effectively manage and administer its affairs. This posed a problem when documents were encrypted. The letters to America often contained long policy discussions and for these documents a short summary of the document in plain text or précis was kept. The précis was usually cryptic and omitted sensitive information such as names and addresses, but at the same time enabled officers at GHQ to refresh their memory of a despatch without having to decode the original again.

  It’s usually extremely difficult to understand the meaning of a despatch by reading the précis unless one is already familiar with the full decryption. As an example, in March 1927 Twomey wrote to an IRA agent, ‘Mr Jones’, in New York: ‘Try and get formulae for these tear gases and mustard gases and [an] idea of [the] plant [or facility] necessary [for production].’ The précis for this sentence merely states: ‘Try and get formulae. Plant’.23 Twomey himself removed the précis on a highly sensitive document that listed American military intelligence provided to the Soviets in America. The document (dated 10 May 1927) is in cipher, and written at the top of the page in handwriting is ‘précis taken by C/S [chief of staff] 6/7/27’.24 The IRA also frequently backdated letters to potentially mislead an unauthorised reader. Usually only the year was changed, so that 1926 was written as 1923 and 1927 as 1924.25

  Telegrams (or cable) were another useful method of communication. As these messages needed to be brief, they could only contain a limited amount of information. Additionally, since they were sent by the post office they were in a sense always intercepted by the authorities and therefore had to be cryptic. Usually they contained a prearranged sentence that signified the sender’s assent or disagreement to a proposal. For instance, Twomey asked the OC in Britain to wire a Mrs Plunkett ‘examination papers correct’ if he had cash for him, and ‘examination papers inaccurate’ if he didn’t. The telegram was to be signed ‘Armstrong’.26 On another occasion Twomey told ‘Mr Jones’ to demand $25,000 from ‘Stephen’ (the Soviet intelligence agent) in return for American military secrets which the IRA was obtaining. Twomey added: ‘If ‘Stephen’ agrees to conditions cable as follows: ‘quotation accepted’, if partially agreed to: ‘can you quote lower’, if he rejects and breaks [the connection with us]: ‘quotation unacceptable’ … You may add any other message which may be intelligible.’27 Occasionally telegrams were sent in cipher, though these would have appeared suspicious to any vigilant employee of the post office. In 1926 Seán MacBride complained that he was unable to decipher two telegrams sent to him in Paris and that ‘it appears to me as if they were interfered with in transmission’.28 Given MacBride’s penchant for espionage and his evident abilities, his suspicion was likely warranted.

  The IRA used invisible ink, though it’s difficult to know how frequently. Naturally one can’t keep on file a collection of documents in invisible ink! In April 1927 ‘Mr Jones’ obtained secret ink, possibly from ‘Stephen’, and passed it on to Moss Twomey by way of Art O’Connor: ‘Gave Art invisible ink. You can use it to a great extent safely. I also showed him how to send communications on picture postcards.’29 Twomey replied: ‘I made a few experiments here and they are quite satisfactory’.30 However, at least for the period 1926/1927, cipher was the primary technique used by the IRA to keep its correspondence secret.

  In the latter half of 1926 three senior IRA leaders, Mick Price, Donal O’Donoghue and George Gilmore were imprisoned in Mountjoy prison. Frank Kerlin and GHQ, however, managed to keep in contact with all three by a variety of methods. The driver of a truck who brought coal to the prison delivered encrypted messages ‘bound in silk paper stuck to the outside of [the] despatch and sealed’ to the prisoners by placing them on the ground at a pre-arranged site. The IRA also likely availed of the services of corrupt warders. The prisoners used any paper they had to send messages out, including toilet paper, which was extremely thin and easy to conceal.31 This is reminiscent of the Provisional IRA’s use in the 1970s of cigarette paper (along with toilet paper) for messages smuggled out of Long Kesh prison. However, to provide Gilmore and his comrades with more writing paper, Kerlin told him: ‘I am getting white paper sent around parcels in future.’32

  Gilmore appears to have suggested to Kerlin to send written notes inside ‘sugar sticks’ and barm brack. Presumably by ‘sugar sticks’ he meant the hard sugar ‘rock’, which to this day is sold in souvenir shops and contains little hidden notes with messages such as ‘A greeting from Ireland’. While traditionally messages or predictions are hidden in barm brack at Halloween, Kerlin replied to Gilmore: ‘[I] will try your suggestion re sugar sticks as soon as I can get some made, but I am sending barm brack or cake at once.’33

  Kerlin also told Gilmore and Price to soak certain letters in water to make a ‘watermark’ visible. It’s unclear what exactly he meant by ‘watermark’. He doesn’t appear to have meant a form of invisible ink, as water usually has to be acidic, alkaline or coloured to reveal an invisible ink. It’s also unlikely to be a reference to a true watermark which is produced with a wire during the manufacturing process of the paper itself. However, if one scratches a message onto paper with a sharp instrument and then soaks the paper in water the message becomes visible and this rather crude method may have been Kerlin’s technique.34 He wrote to Gilmore: ‘Wet in water any letters from your mother, in which there is any reference to your cousin Mary and look for [the] watermark’ and told Price to do the same with ‘any letter from your brother Charlie, in which there is [a] reference to Peg’.35

  Figure 14. Letter from Frank Kerlin, the director of intelligence, to George Gilmore, in Mountjoy prison. It was smuggled in by a man delivering coal to the prison.

  [The] bearer of this despatch is prepared to do anything required. He goes in with coal lorries and says h[e] saw you in [the] hospital grounds. Three or four other lorries go in with him and also some horses and carts. Can you suggest a way by which, this could b[e] availed of? Leave reply to this despatch at the exact place on [the] ground, where [the] bearer is leaving this note for you, and pin it to a piece of the blue hospital cloth to enable [the] bearer to find it easily. When writing [g]ive full details of your location and hours of exercise, also any suggestions re. [an] escape [plan].

  Couriers and the communication network

  Once a message had been prepared, the IRA needed to have it delivered to a secure address. Many letters were sent in the post, while the most sensitive communications, including deliveries of money, were hand carried by a courier.

  As Moss Twomey wrote: ‘Except [for] very secret [letters] the post is quickest and surest.’36 Letters for the post were usually placed inside an inner envelope on which was written the name of the intended recipient, or more likely their pseudonym. This was then placed inside an outer envelope, which was sent to a covering address. The covering address was frequently that of a woman, whom the IRA believed was not under surve
illance by the Garda Special Branch. She then passed the inner envelope on to whomever it was intended for. There were also covering addresses designated specifically for receiving telegrams, newspapers, money orders, etc.

  The list of names and addresses of these covering addresses gives an idea of the extent of support for the IRA throughout all sections of Irish society at the time. Some had Anglo-Irish names, which was likely a deliberate ploy on the part of the IRA, but also reflected that it wasn’t purely a Catholic movement. Letters intended for the IRA’s intelligence officer in Tipperary could be sent to ‘Joyce, [the] Royal Hotel’, Tipperary town,37 while those for the OC in Britain to ‘Miss Lena McCormack, 33 St George’s Court, Gloucester Rd, Kensington, SW 7’.38 And at the other end of the globe, letters for New Zealand were to be sent to: ‘Mr C Bray, 26 Pipitea Street, Wellington’.39 One of the covering addresses for GHQ was: ‘Mr Cowan, C.Y.M.S. [Catholic Young Men’s Society], 9 and 10 Harrington Street, Dublin’. The inner envelope or enclosure was to be addressed to ‘Miss Kearney’.40

  The IRA used multiple covering addresses and changed them whenever there was any suspicion they had been compromised. ‘Jones’ in New York complained to Twomey that: ‘I have only one covering address for mail. I would want at least three and a cable address.’41 The North Mayo brigade wrote to GHQ concerned about the safety of letters after the woman at one of its covering addresses moved and had no relatives nearby to take care of her post. 42

  Twomey sent a letter to Connie Neenan reminding him what covering addresses were appropriate for what types of communications. ‘Send cables to [the] Sweetman brothers, 28 South Frederick Street, Dublin. For newspapers: Miss Una Garvey, 6 Morehampton Road, Donnybrook, Dublin. For parcels, magazines or books: Fitzpatrick Newsagents, Wexford Street, Dublin. For occasional letters: Nurse B Monley, Meath Hospital, Dublin. For dispatches: Miss Alice O’Grady, Clarence Hotel, Wellington Quay, Dublin.’43 Twomey wanted funds raised for the IRA in America to be sent as a money draft to Miss O’Connor: ‘I have already informed you that for the present drafts can be sent to Miss O’Connor [in Leitrim].’44

  He reprimanded Neenan for sending a telegram ‘to [an] address which should only be used only for dispatches. I told you several times – cables to be sent through [the] Sweetmans’.45 The Sweetmans were a prominent nationalist family. The patriarch, John, had been a Home Rule MP and in 1906 helped fund Arthur Griffith’s new party, Sinn Féin. Fr Sweetman ran a school in County Wexford and was also well known for his efforts to cultivate tobacco in Ireland. He was a life-long republican and was associated with the Anti-Imperialist League, which was both an IRA and Soviet front organisation. Another republican in the family, Malachy Sweetman, was arrested by the Free State in 1922 and later escaped from Kilmainham Gaol, while Roger Sweetman had been elected a Sinn Féin MP for Wexford in 1918.46

  The most sensitive correspondence was entrusted to couriers to hand carry. The couriers travelled around Ireland by train, bicycle, bus, motorcar, and even pony and trap, and took the boat to Britain and occasionally to the US. They were predominately women from Cumann na mBan (the women’s republican organisation) or relatives of IRA volunteers. Some of the crew members on transatlantic liners also acted as couriers and, at least during the Anglo-Irish War, teenage members of Na Fianna (the IRA’s version of the boy scouts) carried messages.47 An influential IRA officer, Todd Andrews, wrote that this ‘wonderfully reliable system of communication … was the only really efficient part of the IRA operation during the Civil War’, adding a well intended compliment (but one which nowadays would be taken as patronising): ‘It never failed, thanks to the devotion of these women.’48

  While most IRA couriers were Irish, in March 1926 ‘a Jewish engineer’ on the transatlantic ship the SS American Farmer, by the name of Cohen, delivered despatches to London. He dropped them off at a designated house where he ‘met only the old woman, who met him at the door, [and] took the stuff’. He later received $10 (£2) for his expenses, which included tram and taxi fares. The IRA’s American representative was critical of the OC in Britain for not having met the courier, and showing his appreciation for his services.49 Money, in the form of cash or bank drafts, was also carried by courier. Andy Cooney once asked Jones for funding from America: ‘If you can, send cash by hand without delay. Do so in preference to post.’50

  Couriers frequently delivered despatches to call houses. A call house was a home or business where a visitor could be put in contact with an IRA representative, or which would accept a delivery for the IRA. Call houses were located throughout Ireland and Britain, as well as in New York. Twomey even reported: ‘We have a call house in Montreal.’51 Crew members who smuggled messages or munitions across the Atlantic could hand them in to the Rob Roy pub in Cobh, to be picked up by Mick Burke (a well known local IRA man).52

  When a caller wasn’t known, they would identify themselves by using an agreed code word. Twomey arranged for an officer to travel to Glasgow to make contact with the IRA battalion there, telling him: ‘You will call to Patrick Morin, 10 Robson Street, Aikenhead Road, Glasgow. You will give the name Moore and ask for Bob.’53

  In 1927 the director of intelligence reported to an IRA officer in Portlaoise: ‘We can arrange a line of communication by bus between Maryboro [Portlaoise] and Dublin. Can you let me have a call house for our busman in Maryboro near [the] bus stopping place if possible?’54 To which the officer replied: ‘The busman can call for [the] first time to myself and I will then make arrangements with him.’55 A well known IRA haunt and call house in Dublin was the Exchange hotel. Another correspondence from the director of intelligence to the officer from Portlaoise instructed that: ‘Our friend can call to Miss Fuller, Exchange hotel, Parliament Street on Friday at 3 p.m. He can ask for Kelly.’56

  Requiring couriers to go to a call house rather than making direct contact with the IRA was a useful security precaution, which prevented the courier from having to know the name or address of local IRA members. In 1927 the OC in Britain, George, dismissed a courier codenamed ‘W2’ and warned Twomey: ‘W2 has given a lot of trouble since I finished with him. Now he wants his fare home, which I suppose I will have to give him. I used him as a courier so he knows nothing about [my] offices or hardly anything about my work, so if you should see him be careful not to give him any particulars re the addresses etc. that we were using. Please inform the D/I. [director of intelligence] or any others that he may meet.’57 Throughout these documents George comes across as one of the most careful and security conscious of all the IRA’s officers. Indeed it’s a credit to him that he avoided arrest, despite the intense police activity in London at the time.

  During and after the Civil War the gardaí had success in arresting IRA officers by following the trail of despatches or couriers to them, a technique that was also popular with the British police. Therefore, the more intermediary steps the IRA inserted in the delivery of despatches, the safer were their operatives. Even when Moss Twomey visited London he notified George: ‘I will call to your usual call house’, rather than going directly to his office or digs.58 In June 1927 Moss Twomey again took the boat to Britain and travelled to London to collect money. George warned him: ‘[I] will call at [the] hotel where you stayed last time, at 11 o’clock next Saturday morning. Please try and come yourself. Be careful you are not followed to your hotel.’59 On other occasions officers made contact with George by meeting him in a pub at an agreed time.

  In addition to covering addresses and call houses, the IRA had addresses which they designated safe houses. Safe houses, weren’t directly related to the communications network, but were places where the IRA could hold meetings, store supplies and documents, or where a volunteer could safely spend the night. There was the constant risk of raids by the gardaí and in September 1927 the director of intelligence reported a Special Branch raid on a safe house: ‘Ward’s, Glenmalure House, Rialto was raided last week and a very thorough searching made. This house was used by [the] 4th Battalion [of th
e Dublin Brigade] up to recently.’

  WHATEVER BECAME OF THE IRA’s military prowess and discipline in the years following the Civil War, it still retained a complex and efficient communications system, which rivalled that of any other revolutionary organisation at the time. The network had an elaborate set of security procedures and precautions, enabling it to function efficiently despite the best efforts of the Special Branch and a number of blunders by the IRA. Most importantly, it allowed the IRA to successfully shield its activities from the security services in Britain and America.

  List of alleged IRA covering addresses

  Cooper, Mrs Mary Anne, Cobh, County Cork.60

  Bray, Mr C, 26 Pipitea Street, Wellington, New Zealand.61

  Brown, C/O Schwab Piano House, 148 East 34th Street, New York – for telegrams.62

  Cowan, Mr, Catholic Young Men’s Society, 9 and 10 Harrington Street, Dublin – enclosed envelope to be addressed to Miss Kearney.63

  Crehan, Michael, Menlough, Ballinasloe – letters for the South Galway brigade to be sent to Crehan, and then forwarded to Packie Ruane.64

  Cremin, Miss Mary, 84 Bridge Lane, Golders Green, London NW.65

  Downey, Molly, 65 Webb Street, Smithdown Road, Liverpool.66

  Elie [sic], 4 Rue de la Terrasse, Paris 17 – for telegrams to Seán MacBride.67

  Fitzpatrick’s Newsagents, Wexford Street, Dublin – for parcels, magazines and books.68

  Garvey, Miss Una, 6 Morehampton Road, Donnybrook, Dublin – for newspapers.69

  Kelly, The Poplars, Merryvale Av, Stockton.70

  Kelly, Mrs Andrew, 242 Windsor Place, Brooklyn, New York.71

  Lynch, Miss Florrie, 112 South Circular Road, Dolphin’s Barn, Dublin – enclosed envelope to be addressed to Mr Tom R Cleary.72

  Lynch, 20 Rue de la Paix, Paris – for letters to Seán MacBride, the enclosure was to be marked ‘Ambrose’.73