Heavy Lifting: A Housemover's Journal, continued

Up We Go

Cribbing supports the four ends of the two main beams and must be installed completely level for stability. It's retrofitted under the beams, crossing 6x7 members two on two in a box configuration (Figure 7).

Figure 7.Four-foot lengths of 6x7-inch timbers are stacked to support the main steel H-beams. To ensure stability, the cribbing must be shimmed or shoveled dead level (top left). One layer is blocked solid to support the jack (top right). The unified jacking system manifold also provides an instant readout on the weight each jack lifts (bottom).

The remotely controlled, unified system jacks are placed on a solid layer of timbers placed within the cribbing. Once the cribbing is built as high as possible under the beams, the jacks are individually activated at the central manifold while lookouts call out local conditions at the jacking stations. Any telltale creak or shifting is cause for a halt and possible correction before proceeding. The jacks raise the building in 14-inch lifts, allowing the cribbing to be stacked progressively higher, up to the point where the building can be rolled off the foundation and placed on the dollies (or, if it's going right back onto a replacement foundation, more cribbing). Gauges for each hydraulic line provide feedback on the jacks' lifting force, telling me how much weight each is picking up. All told, this building weighed 35 tons, a relatively light load in moving terms.

To roll the building off (or on) the foundation requires another set of track beams, set perpendicular to the main beams and supported at intervals on cribbing and the foundation itself. The main beams ride on the track beams on heavy-duty bidirectional "skates" (Figure 8).

Figure 8.Two-way Hevi-Haul skates (top), are used to roll a building on or off the foundation as well as for alignment above a new foundation before lowering the house into place. Here, the house is winched forward on one axis (bottom left) and nudged into position with a derrick arm on the other axis (bottom right).

On the Road Again

It's getting more difficult all the time to take a building over the roads. Local regulations and permits are one hurdle to overcome. Cooperation from power and cable utilities is a whole other process with little predictability except for the aggravation involved. Those considerations aside, on reviewing the prospective route for this move, it became obvious that there would be no practical way to move the building intact through the tight turns and narrow restrictions along the way. However, an alternative route presented itself in the surrounding inland waterways and a 6-mile stretch of open ocean. Provided with a little cooperation from wind and sea, we could close the gap between the two accessible road links by floating the house on a barge (see Backfill, 12/03). There's actually plenty of precedent for taking buildings over water — it's been done for centuries — but it's still not business as usual.

On the appointed day, we attached the towing vehicle to the house apparatus and headed slowly down the road to the harbor bulkhead, where a 130-ton crane lifted the house onto the barge. We then had to wait for high tide — a difference of about 3 feet — on the following day to ensure enough water under the hull to clear the shallow bottom along the passage. Once in the open ocean, a second towing vessel hitched alongside the barge and added another knot to our speed (Figure 9).

Figure 9.To stay ahead of powerful outgoing tidal currents, a backup vessel tied up alongside the barge, adding another knot to the speedometer and shaving 25 minutes off the ocean voyage.

Even though the ocean was almost unbelievably calm and flat on this day, we needed to beat the powerful currents created by the outgoing tide at the ocean inlet. Otherwise, the tow could be brought to a standstill at full power. All things considered, I think someone up there was watching our backs on this move. The chimney survived intact, and only minor cracking of the wall plaster at the gable ends resulted from flexing of the main beam ends.

At the far harbor, the crane again stood by to lift the house back onto the dollies for the final, short leg up the road to the new site. There, we set her down on cribbing to rest while the new poured concrete foundation and masonry chimney base were prepared. A stepped ledge in the foundation allowed for an antique brick veneer to approximate the original appearance above grade (Figure 10).

Figure 10.Sufficient brick was salvaged from the original foundation to veneer two-and-a-half sides of the new foundation above grade. A closely matched modern brick blends in behind the front step and ends at a rear corner.

Although the framing was still sound and the house had been safely occupied for many years prior to the move, following restoration it would be opened to the public as a functional historical home. This meant, among other things, that the ancient floor system would have to be reinforced to a commercial rating. The owners hired an engineer to design a retrofit forest of posts and braces in the basement (Figure 11). With only a 6-foot-high ceiling and no wheelchair access, the basement is off-limits to tourists anyway.

Figure 11.The building inspector called for engineered reinforcement to the old, chamfered floor joists. Although the home was safely occupied until 2000, it will now be a public museum and the floor subject to commercial design loads.