A History of Operation Crown
While the United States became increasingly embroiled in Laos and in Vietnam, mounting pressure was being brought to bear on the British Government, as a signatory of SEATO, to go to the assistance of its Allies; but, this pressure was with equal force resisted in Whitehall. In December 1962, however, the Prime Minister, in anticipation of a meeting with President Johnson, wished the United Kingdom to be seen to be playing some part in stemming the march of Communism on the mainland of Asia without, if possible, becoming involved in the fighting. The Americans were by then simultaneously engaged in a massive programme of Special Logistic Aid to Thailand (SLAT) and participation in this might be acceptable as a token of Allied solidarity; this proposition was accordingly put to C-in-C Far East Command. As the work in North Borneo was then practically finished and the revolt in Brunei had not yet erupted, the advent at this juncture of SLAT was welcomed in FARELF as a potentially fruitful field for further endeavour, offering opportunities to gain valuable experience and favorable publicity for the Services. Of the schemes examined by the Chief Engineer FARELF, the construction of an entirely new MRT airfield for use by SEATO forces appeared the most attractive. The site was at Loeng Nok Tha, near Mukdahan. It was not far from Thailand’s eastern frontier with Laos and some 70 miles north of an existing rail and air head at Ubon Ratchathani. In February 1963 this proposal was submitted to Whitehall and came to realization under the style of Operation Crown. Authority to conduct even a preliminary reconnaissance was, however, delayed, awaiting Thai Government authority, until May 1963, by which date the coming dry season (September - April) was uncomfortably close and, more significantly, the situation in Borneo had deteriorated, drastically reducing the availability of men and machines and of transport of all kinds. It was, notwithstanding, agreed to proceed and a team led by CRE SLAT, with a representative of FEAF Airfield Construction Branch, visited the site and produced - in a very short space of time and working in very adverse weather conditions - a proposed design, and a rough estimate of f600,OOO for a strip 5,000 feet long and 120 feet wide with 500-feet overruns and 90-feet berms and one million square feet of associated apron and parking space. More extensive reconnaissance was proscribed for fear of prejudicing the negotiations in which HM Ambassador in Bangkok was simultaneously engaged with the Thai Government regarding their contribution to the cost of the works, so that the CRE designate was constrained to make his early plans on incomplete information and, at first, with no staff. At last, at the end of November, authority came from London to go ahead and CRE FARELF could release his first Engineer Operation Instruction. Conveniently, the completion of the Commonwealth Cantonment at Terendak had by then thrown up the establishment for CRE (Works) FARELF, which was promptly appropriated to this project and, with effect from 1 January 1964, renamed CRE Crown. It had hitherto been envisaged that one field squadron would be employed to set up camp and be followed by another with plant and administrative support to build the airfield and that the whole project would be completed over two dry seasons by June 1965. Owing, however, to the delay in starting and the approach of the rains in May, it was resolved to double the initial effort in Thailand with consequent large additions to the accommodation and logistic requirements there. This turn of events had the effect indirectly of securing for Borneo much-needed and long overdue reinforcements which, though repeatedly asked for from UK, had hitherto as often been refused. Meanwhile, in December 1963, an advance party of CRE Crown was deployed to Mukdahan to begin detailed site investigation work; in particular, to locate construction materials and do a detailed survey of the runway alignment, pre-requisites for confirming or revising the findings of the preliminary reconnaissance team. At the same time, leading elements of 11 Field Squadron established a tented camp on the airfield site. In January they were joined by the rest of the squadron (including its attached troop of RAE), followed by plant detachments from 54 Corps Field Park Squadron, the RNZE, and from 5001 Airfield Construction Squadron RAF and, in February, by 59 Field Squadron, newly arrived from UK. The composition and organization of Crown force at this stage is indicated on the diagram at Figure 9. Machinery was meanwhile brought up from Singapore by sea into Bangkok, whence it was forwarded by rail and road, which necessitated the strengthening of some of the bridges on the way. Air maintenance, limited because of operational demand from Borneo, was from then on to be a continuing constraint on the movement of men and of urgently needed stores. The main effort to begin with was applied to the construction of roads, a helipad and the hutted camp for the workforce. Water for the works was from the outset a recurrent problem and had at one time to be hauled from a distance of 18 miles. By April the camp was ready for occupation and 11 Squadron could be released; the plant, working two shifts a day, had cleared the alignment for the runway and removed top-soil to an average depth of two feet to reach sand suitable for cut and fill operations to form the sub-grade, clay in the sub-grade being replaced by sand. The ground was extremely dry and the whole area became covered with dust, making it unpleasant work in shade temperatures up to 108" Fahrenheit. Progress up to this point was well ahead of schedule, but operations were being increasingly interrupted by un-seasonal rains and, at the end of May, earthmoving was suspended; water supply had, for the time being, ceased to be a problem. In July, after completing a temporary strip for light aircraft, 59 Squadron repaired to Singapore for a period of rest and re-training.The initial design produced by CRE SLAT in June 1963 was for a wearing surface of Pierced Steel Planking (PSP) on a base of compacted laterite and sand, 18 inches thick. The top three inches of the laterite were to be stabilized with bitumen to produce a waterproof seal to the pavement. The findings of the more detailed investigation carried out by the CRE Crown technical team from January to June 1964 led to a re-design of the runway pavement. It was found that the locally-occurring laterite, apart from being much less extensive than expected, contained a high proportion of clay. This rendered the material unsuitable for bitumen stabilization. Also, there were second thoughts about using PSP. The Americans had experienced difficulty with a nearby airfield at Nakhon Phanom surfaced with PSP, where the metal cut the waterproof seal. There was also concern that PSP was unsuitable for the higher tyre pressures being used on modern aircraft and worry about the effect of the metal on electronic equipment. Revised designs were developed by CRE Crown and the final proposal submitted in October 1964 - well into the second dry season of the project - was for a wearing surface of two inches of bitumen macadam on a base of six inches of stabilized laterite, upon a sub-base of compacted laterite and then sand, giving a,total pavement thickness of 22 inches. It was proposed that the base stabilization .should be done using both lime and cement and this method was endorsed by the Road Research Laboratory in the UK. The pavement design was approved by the Chief Engineer FARELF and financial approval for an extra cost of f 38,500 was given by the Treasury in November. Meanwhile in August work had been resumed on site, six full days per week, now hindered once more by acute water shortage and by constant breakdowns in the whole range of aging plant. Because some of the materials had to be collected from sources as much as 200 miles distant, when stabilization began it was at times impossible to keep more than one of the four Howard trains in action. However, the runway base was finished by the end of March in the following year and the macadam surfacing by the end of May, when the New Zealand detachment was withdrawn. Determined efforts to beat the monsoon enabled the control-tower, airfield fencing and lighting to be completed in time for an opening ceremony to be performed on 17 June 1965 by the Thai Minister of Defence in the presence of his Prime Minister and the British Ambassador. It was, however, by now apparent that the cost would overrun the approved estimate by a substantial margin and, furthermore, it would scarcely be possible to finish the outstanding work and evacuate the site by the planned date, 31 October 1965. More alarmingly, it was soon apparent that the airfield was showing signs of failure, with soft patches and rutting. In October 1965, Colonel Engineer Plans (Airfields) in MOD visited Loeng Nok Tha to investigate what residual work was required to reinstate the pavement. In doing his investigation, he identified the most likely causes of failure. The main reason he found was the porosity of the bitumen macadam. This, coupled with an inadequate cross-fall, allowed water to be retained as if in a sponge, from whence it filtered down through cracks and imperfections in the stabilized base to soften the laterite subbase below, sufficient to cause failure. With the benefit of hindsight, it is possible to catalogue many contributary causes of failure. For reasons of economy, the bitumen macadam was very much a marginal design. It could have worked, but the aggregates used were of a poor quality due to local circumstances and the mixing plant was too old and inadequate for the task. The result was a macadam that looked fine when laid but which “stripped” (bitumen-aggregate adhesion failure) when wet. The inadequate cross-fall accentuated the problem. The stabilization generally worked very well, but there were many problems with equipment serviceability, no doubt compounded by the remote location,and the equipment operators were not very experienced. There were doubts too about the quality of the local cement. It was to be expected that there would be minor imperfections in such stablized bases and a waterproof seal was essential. The late rite used for the sub-base was of a very variable quality; comprehensive laboratory testing had indicated a reasonable bearing capacity for this layer, but in the event, the material as laid proved fat weaker. Desirable field trials could not be carried out because of time constraints; the percolating water guaranteed failure. Pending the outcome of technical enquiries, the whole question of SLAT, and of Crown in particular, came under review at high level, with certain circles in Whitehall pressing for a decision to cut the losses and clear out of Thailand as quickly as possible. This un-soldierly proposition was, however, most strongly resisted by the E-in-C, contending with eventual success that, quite apart from political and military considerations, the Royal Engineers should be allowed the opportunity to retrieve their fortunes, to regain confidence in themselves and to restore their reputation in the eyes of the Royal Air Force. This latter was particularly important as the assumption of responsibility for airfield construction by the Royal Engineers from the Royal Air Force was at its height just at this time. Miraculously, the “political uncertainties’’ so feared by the FCO faded away, the Treasury found the funds to finance a complete reconstruction and orders went out in October 1965 for this to be taken in hand. In November, 11 Field Squadron took over from 59 Field Squadron the ongoing works, while the latter moved back to Singapore for re-training. Meanwhile, a new batching and mixing plant was ordered and brought up in time to be taken into use by 59 Field Squadron on their return in May 1966. The resurfacing sequence involved stripping the black top, ensuring that the underlying stabilization was intact, or repairing it where necessary, and then placing an 8-inch layer of pavement quality concrete (PQC). In this phase, the force found itself fully stretched with two concreting parties working alternate 8-hour shifts and others employed on associated and secondary tasks, which included laying black top shoulders, re-turfing, runway and taxiway marking, cutting and sealing joints in the pavement, besides normal camp services and administration. The task was, notwithstanding, all but completed by October, when 59 Squadron had to be taken off the project to assume its new role in support of 3 Commando Brigade, Royal Marines. By then, 11 Squadron was engaged elsewhere, including Vientiane in Laos, whither a detachment had been sent to assist in flood-relief operations. The “Confrontation” in Borneo was, however, then seen to be coming to an end, so 34 Field Squadron, which had arrived in Singapore in September from UK to take part there, was deflected to Thailand to finish off the work. When, in December 1966, the reconstructed airfield was finally proved and handed over, CRE Crown was dissolved, some of its staff going to join the headquarters of CRE (Ops) FARELF and the Establishment cover being transferred to 63 CRE (Construction), which opened in Singapore in January 1967. Thus ended the not altogether happy saga of Loeng Nok Tha. With so little by way of preliminary investigation, the bold decision to proceed was from the first fraught with risk; yet, the risks most feared were - as is often the case - not those that materialised, while the circumstances which led so nearly to failure were at once unpredicted and unpredictable. In the event, no lasting damage was done, for, as the operation neared its end, negotiations were already underway with the Thai Government under which a similar workforce was to remain for a further year to undertake, under the code name Post Crown, road construction and other development projects in the same district.
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Post Crown Project
The original suggestion made in September 1966 to the Thais was that a road should be built North West from Loeng Nok Tha to a village some 25 kilometres away called Ban Khok Klang.,Such a road would provide access in all weathers for several,hithedo isolated communities, while at the same time,contributing materially to the internal security of an area open to communist incursions from across the nearby Mekong river. The Thai Government agreed to pay for and deliver to the site all construction materials, and provide civilian labour; the British were to provide plant and project control staff. The alignment - after several revisions - was finally fixed in November and work started in earnest on 2 January 1967. The initial target of 25 kilometres had been fixed largely because it had been assumed that the Force would have to leave Thailand at the end of 1967. However, in August it was agreed that the British could remain until 1 May 1968 to extend the road westward from Ban Khok towards Nong Phok, some 14 kilometres away, if the Thais extended their existing road from there eastward to meet them. In the event, the link was completed by a combined British Thai force, under British command, working West. Control of the project was exercised under CRE(0ps) '(FARELF) by each OC of the squadron deployed to the task at any one time, who had additional staff including a Thai liaison officer and the FARELF Air Troop RE in support. The main base camp remained at the Crown site, with a forward construction camp at Hong Kong. ;34 Field Squadron, having completed its tasks on the airfield, began work on the road in December and was relieved by 59 Field Squadron in May 1967. In August, 59 Field Squadron was duly relieved by 11 Field Squadron who bore the full brunt of the monsoon. By the end of December - when the original 25 kilometers of road would have been finished - no other unit was immediately at hand to continue the rotation. Accordingly, from January 1968, a composite workforce made up from 54 (FARELF) Support Squadron and one troop each from 51 (Airfields) and 59 Field Squadrons, took over and, with the Air Troop still overhead, brought the extended project to completion. The 40 kilometers long road was formally declared open on 18 April 1968. An impressive ceremonial was mounted by 54 Support Squadron marching past in white No 3 Dress and comparing favorably with a smart detachment of the Royal Thai Army brought in for the occasion. Since the people of Lo eng Nook Thai had virtually no experience of operating or maintaining any form of machine, the,development of water supplies in the surrounding villages began with the provision of hand pumps drawing from shallow wells; but, towards the end, a start was made to introduce a more advanced system, putting down 200 feet deep wells, with electric pumps powered from diesel generators, in association with limited piped distribution and water towers built by the villagers themselves. In this and in other directions training the inhabitants turned out to be a rewarding by-product. Two of them quickly mastered the procedure for setting out,,unsupervised, straightforward sections of road alignment; the 15 bridges (some of five or six spans) were built by teams of two sapper carpenters and 12 Thais, and the 1,700 reinforced concrete pipes required for the 93 culverts were manufactured entirely by villagers under the supervision of a sergeant of the Thai Army; up to 200 were engaged to work on the road, not all on unskilled tasks. Numerous subsidiary projects were carried out by the Sappers - not infrequently in their off-time - with the grateful cooperation of the local populace, before the last of them left the district in November 1968.
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Other Projects
The friendships forged at Lo eng Nook Thai blossomed into yet another programme of projects in another part of the country. In October 1969, an ad hoc Specialist Team RE (Thailand) under 63 CRE (Construction) was formed. A combination of, geological, political and administrative considerations led to the STRE being based at Chom Bung, near Rat Buri and some 50 miles from Bangkok, where it was occupied principally with well drilling and water supply installations, but also with building schools. By the time its programme had been completed in September 1971, the team had drilled eight wells, the deepest of which was 236 feet.
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