Manitowoc 4100W Ringer - Stemat
Stemat owns this interesting Manitowoc 4100W Ringer which is mounted on the crane barge "DINA-M". Today is the crane barge owned by Boskalis. The crane's year of manufacture is approx. 1973.
It is a 300 US ton crane. The crane is build from a standard Manitowoc 4100W crawler crane. The Stemat crane is in the course of the years rebuilt whereby less is still in original state. I think the undercarriage with crawler tracks is removed because of the swingwork with chain in front of the ring.
The cab is also replaced by a larger one.
The superlift boom, at Manitowoc called the 'Fixed Mast' is equal to the main boom of the standard 4100W crawler crane. The mast is 130' long and is fixed to the gantry.
The main boom top has a small offset whereby the lower main beams are in line with the boom sections. The advantage of this is the bigger distance between the load and the boom. There are two 135 tonne hooks reefed. On top of the boom is a fixed jib mounted with a length of 12 meters, still 44 tonnes are to be hoisted over this jib. The jib isn't original.
The housing of the carbody has kept his original shape, but was also rebuilt. The original cab was removed. Normally spoken the carbody is fitted with two drums. The machine of Stemat is extended with two extra hoist winches.
From behind we have a proper sight at the 'Counterweight Carrier Beams', two big beams along the carbody and supported by the ring. The 'Fixed Mast' is attached fixed to these beams with 4 heavy pendants and above the beams is the extra counterweight stacked. The counterweight on the carbody is still original and weights 87,300 lbs.
A detail of the main boom point and the fixed jib.
The minimum boom length is 42 meters and max. 90 meters long.
Some months later I saw the crane in action at the Maasvlakte near Rotterdam (NL). The old seawall was removed.
The big concrete blocks of 45 tons are removed out of the water using the excavator and the 4100W with heavy clamshell loaded on a barge.
A wonderfull and unique machine in the Netherlands!