Bunker-nobbling US megabomb test delayed

Too heavy for the bomb racks, apparently

The World War II style 14-tonne conventional bunker-busting penetrator bomb being developed for the US air force has hit development snags, according to reports. Entry to service will be delayed, and costs have risen.

Flight International reports that the Massive Ordnance Penetrator (MOP) will now be dropped for the first time this June from a B-52 Stratofortress bomber, in a test originally scheduled for last August.

The problems apparently stem from the bomb rack connecting the monster weapon to the aircraft. It has proved impossible to hang the MOP from existing racks, and a whole new subsystem has had to be designed, pushing the programme costs up by $10m (33 per cent) and causing a ten-month delay.

In addition to the ageing B-52, there are also plans to arm the B-2 Stealth bomber with MOPs, originally supposed to be complete early this year. There are as yet no revelations as to how that aspect of the programme is proceeding.

The MOP itself is a comparatively simple proposal, a massive sharpened steel pencil with a comparatively small 2.5 tonne explosive charge inside. Dropped from high in the stratosphere, it will strike its targets at many times the speed of sound and punch through earth or concrete protection with ease before detonation.

Such weapons - for instance the British "Tallboy" and "Grand Slam" penetrators, designed by legendary Brit boffin Barnes Wallis of bouncing-bomb Dambusters fame and termed "earthquake bombs" - were used against hardened Nazi targets in World War II. An even bigger one, the colossal 20-tonne American T12, arrived too late to see action.

Nukes relegated the earthquake bomb to also-ran status for many decades, but nowadays there is a desire in America to nobble bunkers using less drastic methods if possible. In particular, the Pentagon's Threat Reduction Agency - funding the MOP - is concerned with the Iranian nuclear programme.

The US intelligence community just last December said that the Iranian weapons effort was put on hold in 2003, but that it had run for many years before that, with Iran denying aspirations to acquire nukes all the while. The permanent five UN Security Council members, backed by Germany, are still hoping to implement a package of sanctions against Iran unless it ceases uranium enrichment. Even Russia has just expressed some worry about Iran's intentions. Russia is perhaps happier to sell the Iranians reactor fuel than see them enrich their own.

The key to the Iranian atomic effort is the centrifuge farm at Natanz (Google Earth kmz link), buried deep beneath many layers of earth and reinforced concrete. Barring heroic measures such as nukes or a massive raid by normal jets dropping laser-guided smartbombs one after another onto exactly the same spot, a Stealth bomber tooled up with MOPs is the only military pill that could take away the Natanz headache.

American contingency planners will no doubt be glad when they finally have it in their medicine chest.

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