Service of the steamer "Andreas" has had to be discontinued for the present time due to damage in her boilers.
Cracks have appeared in the forward tube wallplate. Before the ultrasound examination of the full plate was undertaken, the hope had sprouted that it would have been feasible that only a portion of the plate would need to be welded in.
However, it appears as the cracks spread also around the fire tube connections and surroundings, the entire plate is affected.
In addition to the openings for the smoke pipes there are also the fire-tubes in this plate wall.
The plate wall there was formed 90° outward and the mouthpiece of the boiler pressure-proof riveted. Below that is found the infamous manhole.
The surrounding edges are riveted to the surrounding boiler walls. The "new" boiler- or pipe-wall also, as always, may not be welded to the existing portions remaining left of the old plate-wall. Rather they must be welded directly to the recessed boiler mouthpieces
and the surrounding boiler wall. Naturally, this task means a serious challenge.
On their part the TÜV [insurance certification similar to UL] and the firm RKD [piping and boiler specialists] have arduously and meticulously measured with ultrasound. A hole in the piping was always further ground out in the hope the cracks were only to be found around the hole and in this case were capable of being welded tight. However, based on the widespread surface area affected, this approach is not possible.
The manner of the cracks make a further use of the boiler installation impossible. In stead of simply radially spreading around the pipe holes and being limited to the surface areas the cracks are to be found within the structure of the material of the boiler itself, similar a flaky pastry. This means that in many areas the material of the back boiler wall itself now exists as two or more layers.
It is highly probable that these cracks have existed since the manufacture of the steel plates and were able to further open at the pipe holes through corrosion, and that the changes in pressure of the boiler in previously varying service requirements, and the discontinuous operation, have enabled their spread in the course of time.

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