Caravelle towbar restored

Lauantai 27.5.2023 - Tuesday Club member

Suomeksi

The original towbar for Caravelle III (SE-DAF), acquired from Sweden by Aviation Museum Society, was brought along. It was used by SAS. The towbar was abandoned by SAS along with the termination of the Caravelle fleet’s career. The towbar had lain decades at Arlanda Airport along SE-DAF.

The towbar was taken under restoration at the Tuesday Club in the autumn of 2022, in a similar fashion as the derelict Super Caravelle towbar was restored, used by Finnair. The SAS towbar is of the first version made by the Sud Aviation industries. For its part the Super Caravelle towbar used by Finnair is of the third and last version. The differences between these towbars are minimal and concern mainly the wheel rack of the towbar.

Along with the spring all the parts of the towbar were refurbished and painted. The last job before assembling the towbar was to repair the wheel rack to working order. When the towbar wheel rack was dismantled in the autumn season, it was noticed that the rim of the other wheel was so far gone that it was unusable. The other wheel’s rim was sound enough to be usable with a bit of welding. A new tyre and inner tube were bought for it and one of the bearings, which had broken when the wheel was dislocated from the axle of the wheel rack. When the rim had received its blue colour, the inner tube and the tyre were fitted in place.

To replace the unusable wheel, we managed, after a spot of searching, to find a wheel with an inner tube looking like the original wheel, and fitting the towbar’s 25 mm axle. A majority of the “wheelbarrow” wheels on sale were made for a 20 mm axle. When the rim of the new wheel had also been painted blue you could hardly tell them apart. The wheels were attached on to the wheel rack’s axles, after which the test assembling of the towbar could be commenced.

The test assembling will be necessary, because the towbar will be transported in parts to the Turku Airport area, where it will be assembled on show next to the ex SAS Caravelle SE-DAF, now being restored as the Finnair “Bluebird”. By test assembling it will be ensured that the assembling in Turku will take place without surprises.

The towbar test assembly was started by setting against each other the flanges of the halves of the towbar. We had to do some thinking, because the guiding pins for the flanges of the towbar halves didn’t line up with their holes so that the lifting handles are in the same line. We established that the towbar halves must have been 180 degrees out of line of each other already when they came to Finland.

This we hadn’t noticed when dismantling the towbar, because the towbar lacked the lifting handles, which would have indicated the position. If they had been there, we would have noticed that one handle was beneath the towbar, the other one above. So our conclusion is that the towbar was wrongly assembled at Arlanda. An indication of this is that in the photos we took before the dismantling of the towbar, the metal support of the towbar which should touch the ground is sticking to the skies.

To solve the problem of test assembling we sawed off the guiding pins and pressed the flanges of both the bar halves against each other so that the lifting handles were above the towbar and lined up properly with each other. After this the flanges were locked to each other with two locking collars around them. The collars were tightened fast by their brackets with bolts. This way the towbar halves had been connected.

Now it was time to attach the wheel rack to the towbar. The wheel rack was attached to the towbar by its attachment collars. The rack wasn’t attached in the middle of the towbar, but some way on the pull loop end side of the centre of gravity. Thus the aircraft towhead end, which connects with the nose gear, weighs down and leans on the ground by its support. Finally we attached the manufacturer’s plaque on the side of the towbar. The towbar is still lacking the Caravelle logo, which will be painted on its side before it will be ready to be delivered to Turku.

The derelict towbar underwent a complete transformation at the hands of the Tuesday Club. It changed from the rusty and partly damaged towbar into a renewed one, resembling the towbars used by the Finnair Caravelle fleet. It received the same appearance as the Finnair Super Caravelle towbar we restored a year ago.

Photos by Lassi Karivalo

Translation by Matti Liuskallio