Replacing a Citroen C1 exhaust

On my way down to York in the C1 I pulled into the excellent Mainsgill Farm Shop for some provisions. As I made my way across the car park there was a rattle from the back.  A quick visual inspection revealed the cause – the exhaust hanger on the back box had snapped and it was resting on the rear beam.

C1 back box with broken hanger

Whilst it was still attached when I left home, it had presumably managed some distance before I had noticed. It wasn’t dragging, and it wasn’t leaking so I figured it would make it the rest of the way to York.

Before heading home, TomB engineering fashioned me a temporary exhaust hanger that was more than adequate to get me back.

Jury rigged C1 exhaust hanger

The culprit was pretty easy to identify – the hanger was heavily corroded and the 10 years of vibrations had caused it to neck to breaking point.

Ncked C1 exhust hanger

The following weekend I took a trip to TMS motor spares to pick up a new back box.  Getting the old back box off proved somewhat challenging – first I had to cut off what was left of the old exhaust clamp as the bolts were more rust than metal.  Then it came to separating the joint with the centre pipe.

C1 exhaust pipe joint

This did not want to budge – despite persuasion with a full tang screwdriver and a mallet.  As it had gone bad I had to cut it off. 

However, I was expecting this to be a butt joint – as on the 2CV – but, once I’d finished cutting, I realised it had been a socket joint…

C1 exhaust joint after cutting

So, at this point I knew I was now going to need a new centre section even if I didn’t want to fully admit it to myself yet –  especially given it was now Saturday afternoon meaning I wouldn’t be able to get a new pipe until Monday morning.

Still, I could still remove the old centre section in preparation.  Fortunately the two spring loaded bolts that went into the cat exit flange weren’t too badly corroded and were only a two swear rating to free up.  Being the same age as the rear section, the centre section was, unsurprisingly, similarly heavy with surface rust even if it wasn’t holed. 

However, once it was off the car and I could have a good look at it I found that the front exhaust hanger was in much the same state as the rear – heavily necked and not far off failing.

Necked C1 exhaust hanger

So it turned out to be fortunate that I’d cut through the wrong bit as it now meant that I was going to be replacing it before it failed and whilst I had everything apart anyway.  If it had failed in a few weeks time and I’d had to spend another weekend under the car swearing at the exhaust I would have blamed past me for not having done the job right in the first place.

There was still one major obstacle to overcome – getting the oxygen sensor out.

C1 exhaust section with oxygen sensor

The Book of Lies™ says “The oxygen sensors are delicate and may not work if dropped or knocked, if the power supply is disrupted, or if any cleaning materials are used on them.”  I translated that to mean: “Dose it in penetrating fluid, apply blow torch until cherry red, clamp with mole grips and beat with a hammer.”

C1 oxygen sensor removal kit

The only alteration I made to that was to substitute the mole grips for a correctly sized 22m spanner.  With the aid of +2 gloves of power and full application of my not inconsiderable body weight, after a few heat cycles it came free and I went backwards, fortunately my landing was cushioned by my not inconsiderable derrière.  A four swear rating for this job.

Reassembly was the reverse of removal – but without a blowtorch and an angle grinder.  Joking aside, everything went back together remarkably easily – the only point of note is there’s a gasket made of compressed wire wool in the joint between the cat and the centre section.

With the exhaust fitted and everything tightened up nicely I turned on the engine to check for leaks – all good!

New C1 exhaust

I was concerned that I might have damaged the oxygen sensor when spraying Super Crack Ultra on the cherry red mounting but the ECU seemed happy.

No fault codes

After a short shakedown it was still holding together so I went for a longer run to get everything fully up to temperature – there were some funky hot metal smells which would have been worrying if I hadn’t just replaced the exhaust but everything held up fine.

Job jobbed.

Blade fuse box for a 2CV

The original 2CV fuse box uses glass fuses in a plastic case glued to the firewall at the back of the engine.  As long as nothing goes wrong with it this works as well as it needs to but it’s not a solution you’d choose to keep if you were changing things.

2CV glass fuse box

As I’ve got a bare wiring loom for my Burton project, and I’ve done the hard work of identifying which connector is which, it was a relatively simple – if time consuming – task to replace each of the old glass fuse terminals with a female blade connector and cover them with an appropriately coloured piece of heat shrink.   These then fit onto the male blade terminals of a generic after market fuse box.

2CV blade fuze box

Whilst there are only five fuses in a standard 2CV fuse box I’ve gone for eight as that gives me room to add fuses for some of the additional circuits I’m going to be adding – notably an electric fuel pump.

2CV wiring loom debugging

Whilst still not objectively easy, having a stripped wiring loom makes it significantly easier to identify which connector is which.  To start with I’ll need the ignition and starter circuits so I can run the engine but having five holes in the wiring loom where the fuses are supposed to go makes figuring out what’s what more difficult than needs be.

So, after an evening probing around with a multimeter I’ve now identified both ends of all five fuses and which of those ends match up.

2CV wiring loom fuse connectors

To make my life easier I have numbered them from 1 to 5:

  1. Instruments, indicator, wipers, alternator field (16A)
  2. Stop, interior and hazard lights (16A)
  3. Near side running lights (10A)
  4. Fog light (16A)
  5. Off side running lights (10A)

Next step will to be connect these up to a blade fuse box which will make life significantly easier and allow for fusing additional circuits.

Land of the silver birch

The silver birch tree in the back garden was the tallest tree in the immediate area and it was quite nice to be able to see when coming home on the train. However, it was also right next to the house so to reduce the risk of roots getting into the foundations or branches damaging the roof it needed to be cut back.

Rear aspect of silver birch before crown reduction

Rear aspect of silver birch after crown reduction

Front aspect of silver birch before crown reduction

Front aspect of silver birch after crown reduction

It’s a bit more of a reduction than was planned but it was dictated by the growing points of the tree.  The leader has now been taken back down below the level of the rest of the crown so as it regrows it should broaden out rather than head straight upwards again.

The day before it was cut I made a point of climbing it, as a boy I knew all the routes up the tree at the bottom of our garden so I owed it to my younger self to make my way up this one.  It was fairly easy and the view from the top was well worth it.

View from the top of the silver birch before pruning

At this point I’m standing about where the new top of the tree is.

New year Hadrian’s Wall walk

Coming out of Gilsland there is a section of Hadrian’s Wall that was built as “narrow wall” (eight Roman feet wide) on top of “broad wall” (ten Roman feet wide).  As the narrow wall is later in date, this indicates that the foundations were built first and the main wall was built afterwards.

Hadrian's Wall at Gilsland

Further on there is a milecastle.

Milecastle at Gilsland

The wings of the milecastle that join into the wall are also built as broad wall and are stepped in to meet the inner face of the narrow wall.  This indicates that the mile castles were built independently and before the main wall.

Milecastle at Gilsland

Further down there is the remains of a bridge abutment. This was significantly modified twice throughout its life as it was presumably damaged by by the river.  To relieve pressure on the structure sluices were put into the wall on the first rebuilding.

Roman bridge relief sluice at Gilsland

As these seemingly didn’t prove sufficient they were widened when it was modified for the second time.

Roman bridge relief sluice at Gilsland

Evie anti-torpedo netting

Piled up at the back of the beach at the Sands of Evie is a section of anti-torpedo netting.  This is made up of interlocking rings of thick gauge galvanised wire, somewhat like chain mail.

Anti-torpedo netting on Evie beach

Where it’s above the high water mark it’s still in good condition but where it’s regularly covered by the salt water it’s got a fair amount of surface rust.

Anti-torpedo netting on Evie beach

The steel hawser that ran across the top is still clearly visible as are a number of joints with shackles attached, I assume this is where the floatation boys were attached.

Anti-torpedo netting on Evie beach Anti-torpedo netting on Evie beach

Hoy Sound Gun Batteries

Hoy Sound forms the main western entrance to Scapa Flow between Hoy and the Mainland’s Stromness peninsula, with the small island of Graemsay in the middle. These batteries are fairly typical of those found at strategic entrance points round Scapa Flow.

Map of Hoy Sound defences

Volunteers’ battery

Next to the campsite some of the remains of the gun platforms for the battery built in 1860 for muzzle loading cannon and is situated such that it covers the entrance to Stromness harbour rather than the entrance to Scapa Flow. It was up-gunned with 4.7 inch breech loaders sometime before 1910 but was overshadowed by the construction of the Hoy Batteries in WWI.

Volunteers' Battery Volunteers' Battery

Links Battery

Walking round the shore path – skirting Stromness golf course that gives the battery its name – the first obvious structure is a twin six pounder QF emplacement of the Links Battery looking out over Clestrain Sound towards Graemsay. With an effective range of 1,500m the six pounders would cover the 1000m of water with ease and be more than a match for light vessels such as motor torpedo boats.

Links Battery emplacementHoy Sound

Further round there is a low searchlight emplacement set into the shore. If the searchlights were being used to find a target in the sound at night they would provide an obvious target so they tended to be placed away from the guns. This covers a similar area to the six pounder emplacement – over towards Graemsay.

Links searchlight emplacement Links searchlight emplacement

Hoy No. 3

In the rough of the golf course the foundations for the WWI Hoy No. 3 battery of three five inch guns can still be made out from the path.

Hoy No 3 battery

Ness Battery

Still further round an higher up the hill there are the emplacements for the main six inch BL guns of the Ness Battery that would have covered the entire Hoy sound. With a seven mile range these guns would have commanded the seaward approach to Hoy Sound and been extremely effective at the close ranges across to Hoy.

Ness Battery Hoy Sound from Ness Battery

There is a guided tour of the Ness Battery that is well worth doing as it not only covers the gun emplacements and supporting structures but also the surviving accommodation huts.

Hoy No. 2

In front of the emplacements of the Ness Battery are the remains of the WWI Hoy No. 2 battery, similar structures to those of Hoy No. 3 but for two six inch guns.


On the rocky high point of the ness overlooking both Stromness and the Ness Battery is Citadel which was the site of an 40mm Bofors anti-aircraft gun in WWII. This is now known as Gun Viewpoint which is at the end of Citadel Road.

The Citadel The Citadel

Hoy No. 1

To the west of Stromness beside Warbeth Road is the location of the WWI Hoy No. 1 battery which, like Hoy No. 2, had two six inch guns. There don’t seem to be any discernible remains but the site has a commanding view over the seaward entrance to Hoy Sound.

View from Hoy No 1 Battery

Skerry Battery

Situated on Hoy the Skerry Battery had two 12 pounder QF guns and searchlight emplacements. The battery is located at the entrance to Burra Sound – between Hoy and Graemsay – which was effectively closed by block ships supplemented with additional anti-submarine obstacles in the channels.

Graemsay and Skerry Batteries from Ness Battery

The majority of Skerry battery still remains in the corner of a farmer’s field. At the rear is a generator building, in the centre is the fire control tower with another building off to the right.

Skerry Battery

The fire control tower has a ground floor room and the first floor main observation room is entered via an exterior stair at the rear of the building.

Skerry Battery

From the fire control tower the whole of Hoy sound and the entrance to Burra sound can bee seen.

View from Skerry Battery fire control tower

The wooden window frames still survive and it’s possible to make out the recesses where the window hinges would have fitted.

Skerry Battery fire control window

The two twelve pounder emplacements are immediately in front of the fire control tower.

Skerry Battery gun emplacement Skerry Battery gun emplacement Skerry Battery gun emplacement

Inside the emplacements there are ready use ammunition lockers in the front corners.

Skerry Battery gun emplacement Skerry Battery gun emplacement Skerry Battery gun emplacement

The guns were situated so as to be able to cover the entire sound.

Skerry Battery gun emplacement

Set into the front of the cliff with their tops level with the field are the two searchlight emplacements.

Skerry Battery searchlight emplacements

Further round and in the lee of a slight dip in the cliff line two concrete Nissen huts still remain.

Skerry Battery nissen huts

Graemsay Battery

The later Graemsay battery, situated next to the Hoy Low lighthouse, consisted of a twin six pounder QF gun emplacement and searchlights that, in combination with the similar guns of the Links Battery, meant by 1944 the main western entrance to Scapa Flow via Clestrain Sound was well covered.

Built late in the war the Graemesay battery is somewhat different from the others, notably it doesn’t have top cover for the gun emplacement – presumably as the threat of air attack had significantly diminished – and it features dispersed beam search lights.

The fire control tower has four levels, the upper two feature panoramic windows.

Graemsay Battery Fire Control Tower Graemsay Battery Fire Control TowerGraemsay Battery Fire Control Tower

Inside, a number of original fixtures still survive.

Graemsay fire control tower fittings Graemsay fire control tower fittings Graemsay fire control tower fittings

The upper floors were accessed by wooden ladders and there are cable runs between the floors set into the walls.

Graemsay battery fire control tower ladder Graemsay battery fire control tower cable runs

The gun emplacement mounted a pair of six pounder QF guns.  The floor is concrete with a metal hexagonal ring to fix the turntable.

Graemsay gun emplacement Graemsay gun emplacement

The outer walls are finished with local stone and this is particularly evident in the ready use ammunition lockers.

Graemsay gun emplacement Graemsay gun emplacement

The emplacement’s traverse covers the entire sound from Hoy to Stromness.

Graemsay battery panorama

The dispersed beam searchlight emplacements are set some way off to the south of the gun emplacement.

Graemsay dispersed beam searchlight emplacements

The dispersed beam emplacements feature two sets of three vertical windows which, judging by the traces of glass, would have been glazed.  There are fittings for two search lights inside.

Graemsay dispersed beam searchlight emplacement
Graemsay dispersed beam searchlight emplacement
Graemsay dispersed beam searchlight emplacement

The inside is painted in two tones, split to match the horizon.

Graemsay dispersed beam searchlight emplacement

There are markings next to the windows that are presumably angles and assist with set up of the dispersed beam.

Graemsay dispersed beam searchlight emplacement markings Graemsay dispersed beam searchlight emplacement markings Graemsay dispersed beam searchlight emplacement markings Graemsay dispersed beam searchlight emplacement markings