Work Day 22nd September 2018

T86
The main tasks for Dave and Pete M on Saturday were painting; a top coat for the radar roof and completing the door side of the radar cabin. Two accompany photos showing the end results. Painting is carried out with a 4” roller and takes quite a while, a job you think won‘t take long but does!

T86 Roof Repaint wm.jpg

T86 Door Side Cabin Repaint wm.jpg

The roof safety switch and access ladder were refitted, see accompanying photo. The roof switch still needs to be rewired and its cover replaced. The cover requires a ¼” UNC hole re-tapping before it can be fitted.

T86 Access Ladder  Refurb wm.jpg

Work continues on refurbishing the cabin fittings and two light brackets are shown in ‘as removed’ condition, these should be refurbished by next week. See the accompanying photo.

T86 Lights Bracket Corrosion wm.jpg

LCP
The simulator was given a good run on Saturday for a photography session and during the day TWO power supplies failed. Although power supplies have failed before this is the first time two failed in one session! The power supplies in question were a 5V 120A (causing intermittent problems with the display system – CHARGE) and a 15V 16A (I/O rack supply). Spares are kept in the LCP and both power supplies have/are being replaced. Pete M was quick to identify the faulty power supplies calling on his experience of the time he was a Ferranti engineer commissioning the MK2A LCP’s at the factory.

Pete H

Advertisements

The Role of Bloodhound 2

This was written by Richard Vernon, BMPG Archivist and Historian, and published on the RAF West Raynham Association Facebook group on 18 September 2018

The principle targets post the reintroduction of UK SAM defences in 1975 would have been low level Su-24 Fencers and Tu-22M Backfires (more likely the former) and reconnaissance Mig-25’s at medium and high altitude. The Tu-96 Bear’s, Tu-22 Blinders and Tu-16 Badgers were stand off missile carriers which were capable of launching their missiles from 150 miles from the target. The standard Soviet long range missile was the AS-4 which came in at Mach 3 and at 80,000 feet. Bloodhound 2’s TIR could track those missiles at useable ranges, but the seeker in the missile couldn’t. On top of this the missile couldn’t reach 80,000 feet and the warhead was optimised to kill large aircraft, not small missiles. The longest range a Bloodhound 2 successfully homed was a impact range of around 68 nautical miles during its service acceptance trials at Woomera in 1964/65 and unless overridden, the systems computer wouldn’t allow an engagement beyond 75NM range. Should WWIII have broken out between 83 and the end of the cold war, a big chunk of Eastern England would have been covered by a Low Level Missile Engagement Zone (LOMEZ) which extended from around 20 miles east off Flamborough head in the North Sea to Doncaster in the north to the Isle of Sheppey and out into North Sea 30 miles east of Clacton on sea to the South. This zone was spilt into 6 lopsided boxes with the north/south centreline running though North Coates, West Raynham and Bawdsey. 85 Sqn covered the front three boxes and 25 Sqn the rest. The LOMEZ extended up to 5000ft above sea level when the zone was active, the missile sections would search for targets within their own boxes and if any target was below 5000 feet, travelling within a certain range of bearings and was flying above a set speed or was jamming, the Missile section could engage immediately. Any target above 5000ft had to be engaged under positive control of the sector control centre at Neatishaed or Squadron control at its ops room level.

Bloodhound 1 wasn’t procured originally for UK air defence as its primary role, but as a Training and Trials weapon to get the RAF into the guided weapon game. This was because when the RAF took control of the system off the Army in 1953 they found it was basically useless in the face of Electronic Countermeasures and Chaff. However the RAF soon realised that to actually gain the knowledge required in how to operate SAM and fighters together, the trials would have to be done on a large-scale and though the system was still pretty useless, it would still be a threat that the soviet’s would have to deal with. Thus the plan was to build a line of Bloodhound 1 sites along the coast from the Humber to the Thames with would provide a barrier defence for London and the Midlands at medium level and these sites would be equipped with a follow on weapon called Blue Envoy which would overcome Bloodhound Mark 1’s limitations. However in 1957 this plan was changed when it was decided that a point defence of the V-bomber and Thor missile sites would be done with Bloodhound Mk 1, which would be then replaced with the Thunderbird Mk 2 being developed for the Army (Blue Envoy being cancelled in May 1957).

Bloodhound 2 came out of design studies done by Bristol and Ferranti in 1957/58 and was part of a twin pronged effort to deal with major threats that neither Bloodhound Mk 1 or Thunderbird Mk 2 could deal with. The major threat was the large high-speed stand-off missile. To deal with this the Bloodhound Mk 3 was proposed. This system used two radars, a Type 87 radar to track the target and a modified Type 83 radar from Bloodhound 1 to track a transponder in the missile and provide command guidance steering commands to the missile from a computer on the ground. The missile was to be fitted with a small nuclear warhead which would allow the system to engage very small high speed targets. To allow the engagement of lower speed larger targets the Bloodhound Mk 2 was proposed which would just use the Type 87 and home on to the target with the missile fitted with a conventional warhead. The intent was the missile section could use either weapon at a flick of a switch. The RAF decided that Bloodhound 2/3 was the way to go and pushed for the weapon development as it solved a lot of basing issues that would have been caused if they had stuck with the much shorter ranged army missile. However in 1960, the Government basically gave up on UK air defence because of the Soviet IRBM threat. They cancelled a major upgrade to the UK air Defence radar system and rerolled it into a combined Air Defence / Air Traffic control system, Cancelled the Blue Streak IRBM program and Bloodhound Mk 3. Bloodhound Mk 2 development continued, however its primary role became a deployable system for air defence of RAF bases in the Middle and Far East where it was more likely that the RAF would be fighting people equipped with manned aircraft and not missiles (Egypt and Indonesia). The UK-based elements were primarily for Training and Reinforcement roles to allow a minimum oversea manning of the overseas bases to save money. UK Air defence was very much a tertiary role for the system when its final operational requirement was released in 1961. The fixed site operational elements in the UK were withdrawn between 1967 and 69 with the drawdown of the V-bomber nuclear deterrent force and the roll out of Polaris missile patrols. The plan was then for 2 squadrons of 6 deployable 4 launcher sections to be based at West Raynham from 1970 onwards for deployable use until the system was phased out.

However, in 1968 NATO introduced its Flexible Response policy which meant that NATO wouldn’t use Nuclear weapons until the Soviets did in any general war. Therefore NATO had to provide its bases in Germany with Hardened facilities on its airbases to allow a reasonable operational life of the aircraft based there. To enhance this they required all bases getting the aircraft shelters and other hardened buildings to be given low level all weather SAM defences and NATO funding for the infrastructure was dependant on this. The only weapon system the RAF had that could do this was Bloodhound, so all of the kit planned for West Raynham was moved to Germany in 1970. This deployment was planned to last until the All Weather Rapier Field Standard B became operational in the early 1980s.

In the early to mid 1970’s the decision was made to build hardened shelters on the RAF and USAF bases in the UK declared to NATO’s SACEUR and SACLANT commands for Nuclear strike, air defence and maritime attack. To get NATO funding for this the user nations (UK and USAF) had to again provide low level air defence. The RAF proposed an area SAM air defence using Bloodhound Mk 2 equipment from storage and returned from Cyprus, with later deployments with equipment returned from West Germany to defend all of the USAF and RAF bases south of the Humber. Anything to the north (all RAF) would get Rapier. NATO agreed with this for the RAF, but had the attitude that the USAF could afford to provide their own SAM defences. This caused the USAF some problems as due to their agreements with the US Army they were not allowed to operate short range SAM and the US Army were not willing to provide them. Therefore, they funded 6 Wing RAF Regiment to defend their bases with Rapier.

Work Day 15th September 2018

On Saturday the final preparations were carried out so that the repainting of the door side of the T86 cabin can be carried out The tasks included the removal old sealant and mastic that was used when the wooden rubbing strips were fixed to the edges of the cabin roof. These wooden strips are not being replaced until all other restoration work on the T86 has been completed.

The main cabin roof is alloy as are the cabin walls so the removing of sealant etc. on the alloy sections was not difficult, just time consuming. See the accompanying image.

T86 Alum Roof Edge wm.jpg

The pedestal roof section was a different matter as the steel pedestal roof overlaps the alloy cabin sides and has suffered from heavy corrosion over the years as water was trapped under the wooden rubbing strips. One challenge was the sheared bolts that secured the wooden strip to the steel section, sheared as they were rusted in place and could not be unscrewed. The sheared bolt stubs protruded from the top edge of the cabin walls, these stubs have now been ground down. Two images show the restoration of the steel roof overlaps.

T86 Steel Roof Edge 1 wm.jpg

All wasted rivets were removed, wasted steel filled, corrosion treatment applied and new rivets fitted.

T86 Steel Roof Edge 2 wm.jpg

Next Saturday is all about yet more painting, hopefully it will be to top coat the main section of the T86 roof and complete the door side of the cabin. There are also repainted covers that can also be fitted.

Peter H

Bloodhound Trials Film – 16 September 1966

We have a copy of a compilation of trials films from six separate RAF Bloodhound firings at the Aberporth range. Each film has a detailed caption including the date of the trial and, where relevant, what went wrong.

Source: http://www.iwm.org.uk/collections/item/object/1060025589

The first couple are of single firings, followed by three sets of Ripple firings (two missiles at three second intervals), all of the Mk 1 variant and fired between 3 February 1961 and 6 March 1962.

The final firing is of a Mk 2 on this date, 16 September, in 1966. A miss distance of 61 feet was achieved. This image shows one of the ram jet covers just after it was ejected.

BH2 Firing wm.jpg

Mike

Work Day 8th September 2018

Yet more painting on Saturday to finish the T86 transmitter air vent, air conditioning and chiller covers.

T86 Covers Final Paint.jpg

A start was also made on painting the door side of the T86 cabin, this clearly shows the contrast between the new paint and the prepared.

T86 Part Paint Door Side of Cabin.jpg

The refurbishing of the T86 roof switch has been completed, at least the main body with the cover still to do. The roof switch is fully functional, the microswitches are OK, the mechanical linkages, and Castel key operation are all ‘A1’. The accompanying images give a classic ‘before and after’, spot that the cable clamp needs to be moved. It’ surprising how heavy the roof switch is!

Before ….                                                     After …..

T86 Roof Switch Before.jpg    T86 Refurbished Roof Switch After.jpg

We have a good mix of thread types and sizes on the LCP and T86, Metric, UNC, UNF and BSF so care is needed in checking we identify the right thread when replacing nuts and bolts. All original steel and zinc coated nuts and bolts are replaced as a matter of course due to corrosion. Cleaning threads once bolts are removed is a standard task, especially as any that are not stainless are badly corroded. The accompanying image shows a UNC tap in place for this purpose.

T86 Cleaning Threads Cabin Wall.jpg

Pete H

Work Day 2nd September 2018

Yes we were there on a Sunday, at least Pete H was!

With the fine weather it was an opportunity to get some more painting done with the focus this time on the insides of the various covers of the T86 cabin. All have to be hand painted due to the ribs and fittings, the external surfaces though will be rollered so will take a lot less time.  Note that our location precludes being able to spray paint.

The T86 roof access ladder is also receiving a top coat and will be finished next Saturday after running out of time. TBelow you can see the collection of items painted and yes, it did take all day but a lot less than the time it took to prepare and prime.

T86 Covers Insides wm.jpg

At third line …
We previously refurbished the pedestal retraction gearbox on the T86 so we could raise and lower the aerials reliably and the T86 roof switch falls into the same category regarding reliability, in this case operation of the aerial brakes. Work is now underway to refurbish the roof switch mechanism and repaint; the image below shows the ‘bits’ from the dismantled switch.

T86 Roof Switch Strip Down wm.jpg

This image shows one problem, it is not a case of rubbing down the existing paintwork more a case of chipping it off! It illustrates the quality of the last paint job by the RAF which was a case of ‘just spray it’.

T86 Removing Paint Roof Switch wm.jpg

We shall be working each Saturday this month (8th, 15th, 22nd and 29th) if you are planning to come and see us … to work!

Pete H

 

Work Days 25th and 27 August 2018

25th August
As restoration work proceeds on the T86 a lot of ‘small’ items need to be refurbished or replaced. Typical are the many corroded machine screws, bolts, nuts and washers. The threads used on the T86 are UNC and UNF as on the LCP except the LCP also had some metric sizes. UNC/UNF items are available but due to cost will be replaced by stainless metric sizes where possible. Stainless nuts and bolts are substantially cheaper than UNC/UNF bolts. A metric replacement option though is not always available, e.g. where an item is an obsolete UNF threaded catch, in this case we have to restore what we have. This image shows the UNF machine screws with one screw being re threaded to make good.

T86 Chiiler Cover Screw Threads wm.jpg

 

While here you see the original steel spring with its stainless replacement, components from a chiller unit cover.

T86 Catch Springs wm.jpg

The original catch had a low grade stainless machine screw, a steel locking nut and steel spring, hence the corrosion caused by these items. The original machine screw has a slotted/hex head which cannot be sourced with a UNF thread these days (metric machine screws can) so it is a case of ‘make do and mend’.

This image shows the inside surface of the roof switch cover after application of a corrosion treatment which will turn black over time.

T86 Corrosion Treatment Roof Safety Switch wm.jpg

It is planned to paint this inside surface with cream Hammerite as per the original colour. A challenge on the cover is to remove a sheared machine screw, some Cobalt tipped drills are on order to ‘hopefully’ help remove the sheared remains.

The T86 roof ladder has two wooded components, a retractable handle and end stops for the upper ends of the ladder rails.Here you will see one of the original end stops and its replacement, obviously not wood!

T86 Roof Ladder Bung wm.jpg

The original wooden end stop has gone beyond the rotten stage and can be best described as fossilised, its structure now more like balsa wood. The replacement is a current, plastic, ladder end stop which will be used until time is available to remanufacture wooden ones to the original pattern … any volunteers please??

27th August
Work has continued on preparing the door side of the cabin for a repaint by removing more of the old sealant along the top roof join and closing up the holes for the wooden rubbing strip securing bolts. Ours is an ex Swedish radar that had the wooden rubbing strips along the top of the cabin whereas the original RAF T86’s did not. Replacing the rubbing strips is something for the future once the rest of the T86 is restored. The accompanying photo from today shows a section of the roof join where the sealant has been removed and the blanking rivets are in place.

T86 Rivets in Coach Screw Holes wm.jpg

Preparation of the roof ladder for a repaint is complete after the delivery of some more anti corrosion primer. See accompanying photo.

T86 Roof Ladder Prepped wm.jpg

The roof switch has been removed for corrosion treatment, painting and a service of the mechanism. The plan was to carry out this work with the switch in situ but it was decided that it fell in to the ‘to awkward’ basket. Shortly after acquiring the T86 we had to remove the roof switch due to problems with the Castel key and the mechanism generally. In refurbishing the T86 some things have to work, the roof switch being one of  those ‘things’ as we needed to get the aerial brakes off. The roof switch  is secured to the cabin wall by four bolts but only one was in position, a second bolt had sheared so another reason to remove the roof switch was to remove the stud left in the cabin wall from the sheared bolt. This photo shows the cabin front wall with the roof switch removed.

T86 Cabin End Roof Switch Removed wm.jpg

And here are  the internals of the roof switch.

T86 Roof Switch Removed wm.jpg

I am pleased to report that the remains of the sheared bolt has been successfully removed. All threads will be re tapped as a matter of course and new stainless bolts will be purchased. It is not true that I wanted to remove the switch so I could paint behind it!

Pete H.