The Threat of Mortar Attack

‘The introduction of the new weapon into the CTO inventory has potentially grave effects for Butterworth’ (Nov 75).

While the Department of Defence’s Nature of Service Branch (NOSB) in its “Background Paper Parliamentary Petition, Dated 3 March 2014, Rifle Company Butterworth 1970-1989” acknowledged there was a possible threat to Butterworth from communist acquired mortars, they fail to expand on the threat. Why?

To quote the NOSB report, starting at paragraph 36:

36.     In 1975 while OC RAAF Base Butterworth believed there is little threat to the Base. DAFI Report No 33 on security at Butterworth in July 1975 notes that:

The possibility of the CT possessing operational mortars adds to the threat against Air Base Butterworth. However, it is most likely that warning of an impending attack would be received prior to the attack taking place. (Cited DAFI Minute INT 8/10/3 Security Situation – Air Base Butterworth Report 33 dated 3 July 1975)

37.     DAFI also saw a threat from indirect weapons such as 81/82mm mortars as expressed in DAFI Report No. 34. (Referenced - SRGD-AF Minute 564/8/28(73) dated 16 July 1975 to DGOR-AF)

38.     On 23 July 1975 the Joint Intelligence Organisation (JIO) advised it could not confirm the CTs had mortars without further substantial evidence, although the advice did discuss the likely challenges faced by a defending force if it was to seek to prevent their use. (Referenced – JIO JSI/85 Security – Butterworth Air Base dated 23 July 1975, to DAFI)

39.     DAFI considered that as a result of increased use of the base by RMAF for airstrikes against CT targets, the base faced a greater chance of becoming a target:

Continued use of the Butterworth as a base for ground-attack against the CT can only increase its attractiveness as a target … From this point of view, the threat to the Air Base Butterworth must be considered to be slowly increasing. (Cited DAFI Minute INT 8/10/3 (150) Security Situation – Air Base Butterworth Report 34 dated 4 August 1975)

 Copies of the four documents referenced above by NOSB are in the possession of the author. These documents, along with others referenced by NOSB, acknowledge the presence of a threat to Butterworth, including the fact it was used by the Malaysians as a ‘base for ground-attack against the CT …’ As demonstrated in other posts, because the threat of attack from an armed enemy known to be active in the region could not be ruled out, Australian service personnel at Butterworth – and, in fact, Peninsular Malaysia – incurred danger from the  hostile forces of an enemy and should therefore receive full repatriation benefits.

As with other sections of NOSB’s report, key evidence is omitted in what can only be seen as an attempt to downplay the threat.

  

DAFI Minute INT 8/10/3 Security Situation – Air Base Butterworth Report 33 dated 3 July 1975

 Quoted in the NOSB report at para. 36 (above).

NOSB quotes para. 9 of this report. Rather than saying ‘…it is most likely that warning of an impending attack would be received prior to the attack taking place’ the document states ‘…it is most unlikely that warning of an impending attack would be received prior to the attack taking place’.

First, the possibility of an attack, whether or not prior warning was received, does not negate the fact that personnel at Butterworth Base ‘incurred danger from the hostile forces of an enemy’. The omission of ‘un’ could have been a ‘typo’. However, a deliberate omission would be consistent with other attempts by NOSB to downplay the risk to Butterworth throughout their report by quoting out of context or ignoring key evidence showing the real state of affairs at the time.

(Document accessed at 564/8/28(174))

Comparison of para. 9 in the original (top) and the NOSB 'quote'

  

  SRGD-AF Minute 564/8/28(73) dated 16 July 1975 to DGOR-AF

Quoted in the NOSB report at para. 37 (above).

This minute acknowledges the OC [Officer Commanding] Butterworth’s belief that there was little threat to the Base (see NOSB para. 36, above). It explains the OC considered any external threat would be posed by rockets similar to those used in other attacks in the country. These had limited range and would expose the firer to villagers friendly to the RAAF in surrounding villages. In para. 3 the author, Wing Commander J.I. Brough, SRGD-AF, reports that the OC’s view was not shared by DAFI:

However, there is some disagreement between this view and that of DAFI, who believes that the CT have 81 or 82 mm mortars (range approx. 3000m) available to them. If this is true in puts an entirely different viewpoint on the matter, and we may have to consider additional security measures, for example, revetments and off-base patrolling by the infantry company.

The Wing Commander added that he thought ‘it prudent to agree to a review of the threat’. Having acknowledged the document, why didn’t NOSB explain the threat.

(Document repositioned to folio 178)

JIO JSI/85 Security – Butterworth Air Base dated 23 July 1975, to DAFI

 Quoted in the NOSB report at para. 38 (above).

The report explained that mortars had greater range than rockets, were more destructive and were much more difficult to defend against:

… A rough rule of thumb is that an infantry battalion deployed in a defensive position can hold a front of 1000 metres in close country and 2000 metres in open country. The attached map shows that at a distance of 3000 metres from the base, a perimeter is formed of 16,000 metres. While it is not suggested that armies will every have enough troops to man such a perimeter, the vulnerability of such an installation to insurgent mortar attacks is readily apparent. The problem posed by mortars is much greater that that posed by 3.5 inch rockets, on the bases of range, destructive power and accuracy.

The author informed that further information on CTO weapons acquisition would be forwarded as it came to hand.

Further documents available to NOSB reveal on-going, escalating concern with the mortar threat.

On 7 October 1975 the Chief of Air Staff (CAS), Air Vice Marshall J.A. Rowland, wrote to the Minister informing of current security concerns and making recommendations for an upcoming meeting of the Minister with the Malaysian Prime Minister. There was increased concern over the security of areas surrounding the Base owing to recent intelligence reports indicating the possibility of communist intentions to launch rocket attacks on bases in Malaysia. He reiterated the concern at the possibility of the CT possessing mortars and expressed the view that a minimum of two infantry battalions were required to provide an effective deterrent against rocket and mortar attacks on the Base. He also acknowledged that ‘Even at this level … security of the area at night must remain doubtful’. Among the recommendations was a request to Malaysia for the allocation of ‘at least one battalion to the area immediately surrounding Butterworth for area defence’. (Security of Butterworth, from J.A. Rowland, CAS, 564/8/28(290).

On 14 October, the Deputy Chief of Air Staff, AVM N.P. McNamara, wrote to DJS as a follow-up to the communication between the CAS and Minister on the 7th. He advised of continued concern over the lack of Malaysian army units around Butterworth while at the same time acknowledging the presence of such could not remove the possibility of an attack.

We also recognise that as Armies and Air Forces have different primary roles, the Air Force commander responsible for the ground defence and security of an Air Base, can never be guaranteed the continuance of Army presence if other priorities influence the local Army Commander. Therefore, at Butterworth, if the allocation of even one battalion were arranged, its tenure of occupancy in a defensive posture is unlikely to be unconditionally assured. In any case, determined DTs would have only limited difficulty in infiltrating onto the airfield or to within 3.5 inch rocket or 81/82mm mortar range. At best, an infantry battalion represents a deterrent presence.

Given the continued vulnerability of the Base to attack, regardless of the outcome of the upcoming meeting with the Malaysian Prime Minister, the DCAS advised the ‘requirement for blast protection of aircraft against ground burst weapons and small arms fire together with aircraft dispersal is currently under review. (Security of Butterworth, N.P. McNamarra, DCAS, 564/8/28(293).

(JSI Document sourced at 568/8/28(233))

 DAFI Minute INT 8/10/3 (150) Security Situation – Air Base Butterworth Report 34 dated 4 August 1975

Quoted in the NOSB report at para. 39 (above).

The minute reported that air strikes were carried out from Butterworth on July 25th and 26th. It also informed of a recent report indicating ‘that the security arrangements at the Base are less than adequate.’  Para.s 6 and 7 state:

… No posts are permanently manned by security forces in the area immediately surrounding Butterworth. Two observation towers which have been built on the eastern boundary are still waiting for the installation of seachlights, and are not manned. External patrolling of the Air Base only takes place if a VIP is visiting, or a positive threat exists.

Local authorities have stated that no Malaysian Security Force contingency plan exists for the reinforcement of Air Base Butterworth. It is not known if such a plan exists at the Ministry of Defence. A locally known plan, which has been implemented once in 1975, allows for the deployment of troops from HQ 6MIB are fairly heavily committed on the Thai/Malaysian border and the size of the force that could be sent to Butterworth depends largely on this commitment. The nearest artillery units to Butterworth are at Taiping.

Of note is the fact that a local contingency plan for the reinforcement of Butterworth was implemented once in 1975 – although no further details are provided.

This advice was included in the above advice to the Minister by the CAS.

An earlier document, ‘Annex A to HQBUT 5/1/AIR (72), dated 11 July 1975, Security – Air Base Butterworth’ confirmed ‘Isolated CT incidents and consequent Security Forces follow-up operations adjacent to Air Base Butterworth have been reported in HQ RAAF Butterworth Intelligence Reports to DAFI’ (included in 564/8/28(230).

(Security Report 34 sourced at 564/8/28(184))

Capture of Unidentified CTO Weapon

 Wing Commander R.A. Brazier, SRGD, in a minute to DGOR-AF dated 21 Nov 75, advised of the recent capture of two yet-to-be identified weapons. He attached ‘a photograph obtained from discreet sources …’ and stated that the fact both weapons were captured in the one engagement indicated the number of weapons was ‘not limited’. He then spelled out what he saw as potential implications for Butterworth:

The introduction of the new weapon into the CTO inventory has potentially grave effects for Butterworth. 3.5” rockets previously used in attacks around BUT have a potential range of 700 metres, but so far have not been used over 400 metres. Weapons which appear to be similar to that capture on 3 Sep, have ranges up to 6,000 m. More importantly, there is now firm evidence that new weapons are being acquired. (564/8/28(309).

According to a hand-written note on the page, the weapons were capture in N.E. Perak, approximately 60 km from Butterworth. A further hand-written comment, dated 12 Jan 76 and signed by the SRGD, noted unconfirmed intelligence indicated the weapon was a mortar manufactured in a ‘backyard foundry in N. Vietnam’ and that this assessment was waiting for confirmation.

Captured CTO Weapon

 

Revetments Constructed at Butterworth

 In response to the perceived threat of rocket and mortar attack revetments were constructed to limit the damage of an attack on the Mirage flight lines. While the date of construction has not been verified, anecdotal evidence suggest it may have been as early as January 1976. If this is the fact, they were built within two to three months of the DCAS advised the DJS they were under consideration.

That they were constructed within 12 months of the matter being raised by the DCAS in response to mortar and rocket attacks is confirmed by the draft AUSTEO document ‘The RAAF Presence at Butterworth’, attached to the Department of Defence Minute, ‘Review of Butterworth Deployment’, written by R.N. Hamilton, A/First Assistant Secretary, Strategic & International Policy Division, dated 22 October 1976 (Reference: DEF 270/1/4, included in 696/6/4/6 PART 3 (282). Paragraphs 20 and 21 are copied below:

20. The likelihood of a terrorist attack endangering the RAAF deployment in the immediate future is presently assessed to be low. It would probably – but not necessarily – be associated with a significant escalation of CPM activity. This is presently assessed as unlikely. It would probably not occur without warning.

21. If such an attack did occur, however, its implications would be serious. Its most likely form would be an attack of short duration on the base using indirect fire from light mortars of small rockets. There is also the possibility of discriminate of indiscriminate acts of terrorism in the Butterworth or Penang areas generally. In either case Australian personnel – including dependants – and equipment would be endangered. Action has recently been taken to construct revetments to give some protection to the Australian aircraft at Butterworth against attack. The need for improved security on and off the base has also been recognised.

  

Conclusion

 Evidence omitted by NOSB demonstrates that senior Defence and Government officials held serious concerns over what they saw as an escalating security threat to Butterworth that resulted in the construction of revetments to protect the Mirage fleet from possible rocket and mortar attacks. That this evidence was ignored by NOSB in what can only be seen as an attempt to hide the real threat to Butterworth must call in to question their impartiality and objectivity on the matter.

Sources

National Australian Archives:

• NAA: 568/8/28 PART 8, RAAF Butterworth – Ground defence plans

• NAA: 696/6/4/5 PART 3, Butterworth Base - General