Memorabila 8 - FSPB Coral
OPERATION TOAN THANG
5 x RT-524
TF Comd Net NCS
6 x AN/PRC-25
TF Comd Net Emergency
(Loc TF CP)
RR Back-up (Det 110 Sig
2 x AN/PRC-47
TF Comd Net (HF) - was
4 x Antenna RC-292
b. Radio Relay
(53rd US Sig Bn) 2 FFV channels
(53rd US Sig Bn) 2 FFV Comcen
(Det 110 Sig Sqn) 1 ATF (Rear) channels
Shelter - Equipment
AN/MTC-7 (Switchboard Shelter)
Plus associated cipher equipment
d. d. Line
Telephone Sets "K"
15 miles D10
1000 feet 5 pair plastic
1500 feet 26 pair
1 x Intercom system (TF HQ)
1 x 21/2 Ton AN/MRC-73 (53rd US Sig Bn)
1 x 1 Ton AN/MGC-17 (53rd US Sig Bn) plus power trailers
1 x 5 Ton AN/MRC-69 (110 Sig Sqn Det)
1 x 3/4 Ton AN/GRC-106 (110 Sig Sqn Det)
1 x 21/2 Ton AN/MGC-17 and AN/MTC-7
4 x 3/4 Ton Stores/Personnel/Tech Maint
3 x M60
2 x M79
2 x SLR (Heavy Barrel)
35 x M16, F1 and SLR (Personal Weapons)
22. Sigs Area Layout See Annex "F"
a. KIA Sig A.H. YOUNG - 16 May 68
b. WIA Sig R. E. GAMBLE - 13 May 68
Sig J. F. KOOSACHE - 16 May 68
Sig I. P. CROSTHWAITE - 16 May 68
24. The communications provided throughout the operation are detailed in the Sig Instructions attached as Annexures C, D, and E. The communications were effective and reliable at all times.
a. VHF. The RT-524 again proved particularly suitable as a control station set. It was necessary to reduce the operating temperature of the set to maintain its performance. Electric fans blowing air over the top and rear of the sets were used (the ambient temperature at this time of the year very high). By elevating the Comd Net RC-292 to a height of 45 feet using 6 Deeko Hast sections, VHF communications were maintained to NUI DAT (80 Kilometres) without employment of a re-transmission detachment.
b. HF. No major difficulties were experienced with the AN/GRC-106 RR back up. The need did not arise to activate the AN/PRC-47 Comd Net HF.
26. Batteries Secondary
a. Prior to the operation some of the radio batteries had been replaced by 12V, 150AH types (Cat No 6140-66-018-3334). Although obtained as an in lieu item due to non-availability of 75 AH, these batteries were ideal. Carrying handles are fitted. One bank of four batteries powered three RT-524. A second bank of two supplied power to the Monitor/Section Set.
b. To avoid the presence of fumes in the bunker whilst batteries are on charge, the battery banks were located in separate sandbagged enclosure on ground level. The battery charger was in an adjacent enclosure.
27. Battery Charging Equipment. The current 300 Watt charger is inadequate. It does not operate satisfactorily in hot weather even in good condition. A 28V DC generator, recently purchased in theatre to power the AN/GRC-106, was ultimately used as the prime battery charger.
a. The AN/MRC-17 did not prove successful due to its small size (See Quarterly Report 30 Jun 68). The equipment was dismounted and set up on tables in the bunker. The problems of heat, humidity and dust were again evident. Fans were used to blow air across the KW-7s and TH5/TGs to reduce the operating temperature. Even so, periodic changes of KW-7s were necessary to allow equipments to cool down.
b. The average daily formal traffic passed totaled 15 messages in and 13 messages out. The provision of reliable RR Telephone circuits has reduced signal traffic to those classified messages which cannot be passed over the telephone.
29. SDS/ADS/Air Courier Services
a. The demand for air support within the Task Force has always prevented the allocation of a helicopter specifically for ADA. Use is invariably made of aircraft primarily concerned with administrative support, which never operate on a firm time schedule. Much time is wasted by DRs waiting for aircraft. Further, where a DR cannot be carried on the aircraft, reliance for the safe custody of the SDS bag has to be left to the crew.
b. Three local SDS runs operated daily commencing 0900 hours, 1300 hours and 1600 hours.
30. Radio Relay
a. Both the 53rd US Sig Bn system to 2 FFV and the 110 Sig Sqn system to HQ 1 ATF (Main) provided good channels with little circuit outage.
b. The tails of the circuit channels (1 ATF CP to 2 FFV TOC) were duplicated at CORAL, one run being overhead, the second being buried. Both runs were cut on the 16 May however, the overhead by shrapnel and the UG by direct mortar hit. The effort involved in burying cables to a depth where direct mortar hits do not cause damage would be beyond the resources available in the Sig Sqn. The possibility of fitting a narrow trench digging bucket chain to a "Howard" Rotary Hoe type machine could be worthy of investigation.
c. There is a need to carry ample 26 pair cable to allow flexibility in positioning the RR Terminals in relation of the Sigcen and the line frame. On this occasion cable had to be loaned to 53rd US Sig Bn to enable the AN/MRC-73 to be located in the most favourable position.
d. Similarly additional aerial co-axial feeder should be carried to enable the best placement of the aerials in relation to the shelter.
e. The antenna erected for the Aust RR System was located in the open perimeter strip and protruded above the general tree line. From the mortar base plate position used by the enemy on 16 May, the antenna was clearly visible. It is possible that the antenna was used as a general aiming point which could explain why the Sigs area received the initial barrage on 16 May attack. Then again it is possible that a deliberate attempt was made to disrupt communications vital for the calling of fire support.
a. Approximately 15 miles of D10 was used on the operation. The usual problems of line being cut by APCs, tanks and engineer plant occurred during the early build up of the FSPB. The effort required to bury cable is not initially available when the Task Force deploys (See Para 30b). The Sqn currently uses five pair plastic cable to run to key feeder points in the area of FSPBs.
b. The line patch frame in future will be located next to the switchboard in the bunker. This will avoid the need to construct a sandbagged frame enclosure and light can be used for repair work by night.
c. The remote lines between the VHF Radio Bunker and the Task Force CP were cut by shrapnel during the attack on the 16 May. New lines were run and communications via the RT-524 restored in a very short time. During this interval the emergency AN/PRC-25 in the Task Force CP was used. A duplicate set of remote lines is normally buried. There had not been sufficient time to carry out this task prior to the attack.
32. Suspected Enemy Jamming. On 15 may at approximately 1515 hours following a contact report the Task Force Comd Net was affected by what appeared to be a noise generated signal. The signal was of 100 Kc/s bandwidth and low power. None of the sub-stations on the net replied to a call from the control station. A frequency change was broadcast (by designator). The frequency change was also passed on the artillery net. All sub-stations responded to the change. Within five minutes the noise signal re-appeared on the new frequency. An immediate change to the original Comd Net frequency was instituted. No change to the original Comd Net frequency was instituted. No further interference occurred on the Comd Net. However, on the same day at approximately 1730 hours a similar signal affected the local defence net. The frequency was changed and further interference did not occur.
33. Subsequent investigation revealed that where as the RT-524 Control Station could over-ride the noise signal the AN/PRC-25s on the sub-station could not. The sub-stations could thus hear control but control was not able to hear the sub-stations.
34. Learnt Lessons
a. Sleeping/Weapon Pits. Individual sleeping/weapon pits were dug initially. It is perhaps desirable in a unit where the majority of personnel are young and inexperienced to use two man rather than one man pits. In this way mutual moral support can be given and a better opportunity to discern the stage at which the mortar/rocket attack has passed and the ground attack has commenced.
b. RR Antenna Sitting. Where possible care should be taken in the sitting of large RR type antenna to ensure that they are backed by foliage from the enemy direction of view.
c. Defence Structure Stores. Where lift capability exists it is preferable to carry basic defence structure stores (timber, roofing iron) with the equipment. In the initial build up of a CORAL type base there is insufficient material of this type to meet all needs. Timber beams, PSP, and roofing iron is gradually being obtained for this purpose in future. The use of "CONEX" type shelters referred to in Quarterly Report of 30 Jun would mollify this requirement.
d. Defence and Employment Section. On future operations it is proposed to raise a D and E Section of one NCO and ten to twelve men. The role of this section will be to provide a force whose sole purpose is to construct defences and man the perimeter pits. This section will ease the pressure on the remaining personnel of the Fwd Op Sigs Gp in the first few days of deployment. Once satisfactory defences are completed thee section would return to NUI DAT. If sufficient notice of deployment is given it is proposed that the D&E Section would undergo concentrated weapon handling and practice firing course.
35. Re-emphasised Lessons
a. Area Layout. The layout of the Sigs area must provide for defence in depth. The layout at FSPB CORAL although reasonable in this regard, will be improved in future operations (See Annex F).
b. Alternate Cable Routing. The establishment of alternate cable routes for the command links as soon as possible after deployment could avoid the requirement to run new lines under the hazardous conditions during an attack.
36. Emergency CP Control Set. Where a remote Radio Bunker is used it is essential to provide an emergency radio set in the Task Force CP.
37. Protective Cover. To reduce the risk of casualties to the minimum it is essential that each individual be accommodated below ground level by stand-to on the first day of deployment. Furthermore, where humanly possible, overhead cover should be constructed by the same time.
38. Rapid Deployment. When deploying for an operation in this theatre the possibility of having to re-deploy at short notice into a completely different situation must be borne in mind. On operation TOAN THANG the requirement arise to deploy from within an established and protected base camp into an enemy controlled area. Twenty four hours notice was given for the redeployment in this case.
39. Operation TOAN THANG provided the Task Force Signal Squadron with the opportunity to test itself under most of the contingencies likely to be met in the theatre; viz
a. Dual Deployment:
(1) From the NUI DAT Base to another base area.
(2) From a base area into an enemy controlled area in the field.
b. The communications provide, encompassed the full range of facilities
available to the squadron and were established over the greatest range
c. Maintenance of communications under enemy fire.
40. The Operation proved an invaluable experience for the Squadron. It is to the credit of those concerned that in spite of the arduous and often dangerous conditions, at no time did a loss of command communications occur.
N. C. MUNRO
OC, 104 Sig Sqn
Annex A -
AO's MURRAY BRIDGE and BELIZE (map overview)
(Murray Bridge - AO Hunter (FSPB Evans), AO Nepean (FSPB Hunt) and AO Swan - AO Belize (FSPBs Wattle and Cedar))
Annex B -
AO's SURFERS and SURFERS II (map overview)
(Surfers - AO Manly (FSPB Coogee) and AO Bondi (FSPB Coral) and Surfers II - AO Newport (FSPB Balmoral))
Annex C - Sig Instr 3/68 (Bearcat)
Annex D - Sig Instr 5/68 (FSPB Coral)
Annex E - Sig Instr 6/68 (Evacuation of FSPB Coral)
Annex F - Sigs Area layout (FSPB Coral)
Annex G - Fwd Op Sig Gp
1. Refer Paragraph 9 - Party:
TF Sig Officer -
Norm Munro (OC, 104 Sig Sqn)
Driver Batman - Anthony Aikman
Radio Operators - Philip Clohesy and John Koosache (WIA 16 May 1968)
Linemen Field - Rowan Gamble (WIA 13 May 1968) and Terrence Rochester
"For the record, I was wounded in the left leg, and the left side of the
head. The leg wound entered through the multiply
seam of the greens. This slowed the impact quite a bit. It
could have been a lot worse.
The one to the head, was light shrapnel. Which wasn't taken
out until years later. But
the brim of my green floppy hat, was full of holes. If I had
been sitting further left, I might not be here to
tell about it. I guess my time wasn't up."
Photo 2 - Sig Bob Parkyn's M16 with captured enemy weapons. Enemy weapon owners are dead! Bob was a member of the 104 Sig Sqn Radio Detachment with 1RAR at FSPB Coral.
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