GAM Aldaiturriaga is a big Spanish rentalcompany of construction machinery, also some cranes like this Grove GMK5100.
The crane was standing on the yard in Pamplona (ES) and was used to unload pieces of a Terex CC 1800-1. It is a 100 tonne crane with YOM 2004.
The crane outrigger base is 7.8 x 7.5 metres and the mass of the crane is 60 tonnes. The crane brings 20 tonnes of counterweight with itself, but is extendable up to 31 tonnes.
The main boom is 51 metres long and extendable with 18 metres of folding jib. GAM means General de Alquiler de Maquinaria.
The lower engine is a Mercedes Benz OM502LA 8 cylinder with 469 hp. The upper engine is also a Mercedes Benz, but with an OM904LA with 177 hp.
As far as I know this crane isn't owned anymore by GAM because it's traded by a Dutch trader.
Closing with a detail of the cab.