About half of our basement sets on a 16" wide shaped limestone wall held together with mortar from the 1870s. It extends just over 4 feet and sits on undistributed compacted dirt. We are wanting to underpin the wall in this area of the basement to achieve full 8' foot tall walls by digging the existing wall out in 20" wide sections. Each section would first have a 8" x 20" x 16" reinforced concrete footer placed on the bottom. On top of this would be placed a reinforced 2 cement block wide and deep column which will be filled with cement. The remaining gap between the existing limestone wall and the block underpinning would be filled with expanding concrete. As a extra safety precaution I'd lid to use a temporary brace under the section of limestone wall section from which the dirt will be removed. Based upon years of driving forklift this could easily be accomplished by placing a single forklift fork under the wall section with an additional extension added to the fork to provide access (cribbing would of course be placed under the fork since hydraulics do fail). Using an actual forklift is; however, not an option due to cost and access issues. I've looked at foundation jacks; which are essentially piles with a "L" shaped lifting shelf attached to them; however, they are not an option as they are placed on the outside of the foundation and because they would provide no working access if placed inside. The shelf used on these jacks are also too shallow as we want support to extend under the full width of the wall. I've previously experience building our own four car garage and attached shop by hand including digging the foundation and basement entrance by hand. Its been over 10 years and no cracks, even in the sidewall, as build stuff to last and do the proper research beforehand. Anyone aware of a jack or lift that might work for such a situation. I've not quite found anything to date. About the only thing that might come close is a manual scissors pallet with an extension placed on one of the forks; however, one might have problems with finding the right fork and the fork would need to be able to support around 4,000 pounds as each section of limestone would weigh around 1,500 pounds. Of course each section of the wall is partially supported by neighboring wall sections but its better to be safe than sorry and one needs to account for the amount of leverage caused by focal point.