Abstract: A double walled riser sump has an annular space between the two walls. The provision of the annular space provides for monitoring the integrity of the two walls of the sump. The two walls of the sump are preferably separated by a thin film or a distance fabric that allows the passage of fluids, and preferably liquids. The annular space may be in fluid communication with a reservoir holding a monitoring fluid and positioned near the top of the sump to be easily accessible. In some embodiments, a top of the riser sump is also double walled and the top annular space is in fluid communication with the annular space between the vertical walls. If a leak develops in either wall of the sump, a corresponding drop in the fluid level of the reservoir will occur.

Abstract: A method and apparatus for casting straps onto the plate lugs of battery cell elements. The apparatus includes a rotatably indexable table having a plurality of mold and element carrying stations which each are successively indexed through a plurality of operating stations, including an element loading station, an element lug alignment station, a molten-metal pouring station, a lug fluxing station, a casting station, a plurality of mold cooling stations, and an element unloading station. The mold of each table station is adapted for efficient and precisely controlled electrical resistance heating and forced-air cooling during each cycle of operation. In the illustrated embodiment, each table-station mold is successively heated from electrical sources at a plurality of operating stations upon indexing of the respective table station to such operating stations and is cooled by directing air through air-direction tubes mounted on each table station in close proximity to the respective mold.