By Anthony R.D. Porter, Contributor 
The Royal Artillery Store constructed in 1888. Affectionately known as the "Giddy House", this red brick building was affected by the earthquake of 1907, which did severe damage islandwide. It tilts at an angle of 17 degrees and not 45 degrees as is often reported. - Contributed
ANOTHER LITTLE known or appreciated feature of Port Royal is the extensive tract of land that has been built up by deposition since the great earthquake of 1692. According to one historical source, at the time of the earthquake the town occupied an area of about 60 acres (24 hectares), but much of this sank leaving only about 25 acres (10 hectares) of dry surface area.
One of the consequences of this was the further isolation of the Port Royal Cay, as a large gap of shallow water (several hundred metres wide) separated the surviving town from the rest of the Palisadoes spit. With the passage of time, however, the gap slowly began to fill in by the natural deposition of sand and gravel. But, according to the records, this process was aided by the residents of Port Royal, who sank old naval vessels and boats (loaded with stones) in the gap, to speed up the process of accretion.
Surviving maps show that the island remained unconnected at surface (that is, sea level) until about the mid-1750s. Since then deposition of sand and gravel has been rapidly transforming the South and Eastern sides of the coastline, while on the Kingston Harbour side, very little has changed.
The most dramatic effect of this depositional activity is illustrated by the present position of Fort Charles, which in 1692, was situated between the sea and Chocolata Hole, with the waves probably lapping at or near the base of outer wall facing Gun Cay. Today, Fort Charles is stranded inland, with the coastline now lying about 1,000 feet (about 300 metres) to the Southeast. In contrast, the gap between Port Royal and Gun Cay has narrowed considerably, and in time probably in another 400 years Gun Cay and other coral banks could be joined to the mainland assuming, of course, that human nature does not intervene (for example, dredging, and so on).
Another interesting spin-off of these physical processes is the sociological impact they have had on the development of Port Royal since 1692. The attached map shows the position of the coastline pre-1692 and at various intervals since then up to the present day. It is estimated that between 1692 and 2002 a period of 310 years more than 95 acres (or 38 hectares) have been built up, in the region extending south and south westwards from the Lagoon, to the coastline near the Coast Guard base.
RAIL LINE AND HOUSING
In the early 1880s plans to further strengthen the defences of Port Royal were implemented. These included the Rocky Point Fort (to the east of the Naval Cemetery) and the Prince Albert and Victoria Batteries. The latter, including the Royal Artillery Store, Gun Pit and concrete parapet wall, were then sited close to the shoreline, which extended south eastwards to more than 300 feet from the front of Fort Charles. At that time there was no road along the Palisadoes spit to Port Royal. In fact, the road was not opened until 1936.
So, the British installed a light rail system to move the huge coastal guns, ammunition, men and building materials from the shoreline inland, over the unconsolidated beach sand and gravel deposits. In 1907 it was damaged by the same earthquake that triggered the liquefaction of the sand that caused the 'Giddy House' to tilt at an angle of about 170 from the vertical. Today, not much remains of the line, but the suggestion has been made, by at least one historian, that if Port Royal should ever be restored and marketed as a historic attraction, then another rail system could be included as part of the tourism package (as is done in many theme parks worldwide).
- Anthony R.D. Porter, former chief geologist, Alcan Jamaica/WINDALCO & Gleaner Honour Awardee for Science & Technology (2001).
