Rabbi David Shmidel of the organization said he was concerned that descendants from the ancient Jewish priestly class – typically identified by the last name Cohen – would not be able to ride the tram because of a biblical prohibition against contact with graves. So his group built an above-ground structure around one burial cave, complete with strategically placed concrete slabs and large metal air pipes on both sides. According to his interpretation of Jewish law, the structure would direct the graves' impurity away from passengers.
Ynet has a good piece on Jerusalem's new light rail line which is due to be operational next month. It details objections to the project from Palestinians, and delays to completion of the project caused by engineering errors archeology digs – and haredi grave issues:
…Before the tracks were laid, builders encountered a religious dilemma: Two Jewish burial plots, believed to date back 2,000 years, were discovered along the tram route. Tampering with graves at construction sites often ignites the fury of ultra-Orthodox Jews, so the light rail's developers consulted Atra Kadisha, an ultra-Orthodox Jewish organization that cares for old graves.
Rabbi David Shmidel of the organization said he was concerned that descendants from the ancient Jewish priestly class – typically identified by the last name Cohen – would not be able to ride the tram because of a biblical prohibition against contact with graves.
So his group built an above-ground structure around one burial cave, complete with strategically placed concrete slabs and large metal air pipes on both sides. According to his interpretation of Jewish law, the structure would direct the graves' impurity away from passengers. It held up the project for nearly half a year, but light rail developers agreed to reroute the tracks around the structure.…
It would seem to me that under Jewish law, the light rail cars themselves are considered to be separate domains from the ground around them, and therefore no structure, concrete slabs and air pipes would be needed. If not, a simple fence would have created a separate domain for the burial plots and solved the problem.
Instead, haredim delayed the project unnecessarily and put even more financial strain on the downtown businesses that are suffering while the light rail line is being built.