Potain Obendreher

[erkkil 1]

aber Ich glaube ...

The bigger Potain is a 763/764/765 with a specially shortened jib end. Potain 743 has a mast cross section of 1.6 m and 8 bolts in each section corner connection, 76x has mast cross section of 2 m and 6 bolts in each corner (look at the connections in the pics)..

The other one is indeed some Potain 42X (426, 427 or 428). The predecessor of Potain 426 was a 506D6, but it has smaller counterweight blocks than this crane. Otherways it is very difficult to recognize.

regards,
erkki

[roadix 0]

@erkkil:
Wow, great - I always wondered, which type I might have seen! Thanks!

[jeff 0]

The 506D6 model was rather different from 42x models with cab integrated to a mast section. The 506D6 had a lowest cathead and 2 tie bars. 42x models had one tie bar only. Like on 427D, the 506D6 counterweight was no broader than the counterjib width, but on 427 post D and 428 models it was broader. The erection system of 506D6 and 42x models was different too.

Regards,
jeff

[erkkil 1]

Yes, but: I have seen two different 506d6:s:

1 The previous ones were like you described. I have a datasheet and a service manual of that type. It indeed has a two-tie jib, and cab in mast section.
2 The later version had a similar cabin than the older, but the rotating part (jibs and mast top) was (almost) like in 426 or 427.

The later 42X:s had cabin above the slewing ring, so it was turning with jib.

I have seen at least 506:s of the later version in Finland: One was building a "Sokos" deparment store in Tampere in 1975, another is still stored in a factory yard (dismantled) near the town of Forssa.

Potain models 426 and 427 still exist here, most serve as factory cranes:
- Near city of Hyvinkää (50 km north from Helsinki)
- Just beside road nr. 6 in Taavetti, Luumäki, (south-eastern Finland)
- Factory area in Forssa, near tower crane training facility

[jeff 0]

Thanks for your info. I don't know the later version of 506D6. Here in France, I've seen some of the first version.

There are 427, 428 and 429 still active in France, mainly in factories. These models are espacially the later version with the cab over the slewing ring. Very nice cranes...