My Lords, I too begin by thanking the noble Lord, Lord Harris of Haringey, for securing this debate. I also thank all noble Lords for the fascinating contributions that we have been privileged to hear in your Lordships’ House this evening. Since I arrived here a year ago, I have never had a day without learning something new and this evening is absolutely no exception. I will endeavour to cover the points raised, but if time does not permit me I will write to noble Lords on any outstanding issues.
As all noble Lords have pointed out, the SS “Richard Montgomery” is very different from most World War II wrecks in UK waters. It rests in shallow water near residentially populated areas and approximately 1,400 tonnes of explosive munitions remain on board. That figure is the net explosive weight, rather than the net cargo weight, which is what I believe the noble Lord, Lord Harris, was referring to. I think that, rather than the mystery disappearance of munitions, explains the discrepancy.
We understand that much of the explosive content still aboard is TNT, but we also understand that there is white phosphorus on the wreck in the form of signals and smoke bombs, which are in the deep tanks, and the surveys show no breaches. I will double-check this following the debate but my information is that we have no recorded examples of phosphorus escaping.
Several noble Lords, including the noble Lords, Lord Harris and Lord Addington, asked about the state of the munitions. Although we are not in a position to understand fully the condition of the munitions, we believe that the TNT is likely to be inert because the fuses have degraded over time. I am afraid we do not have an estimate of the cost of removing the munitions, as the noble Lord, Lord Rosser requested.