kh 43 clearing rubble for 20+ turns?

[raizer]

ok Keith and I have been crowing about arty set up in our kh43 game-here's another problem we seem to be having: Clearing rubble off this primary road...we have been at it every turn for 20 turns now and no luck-for about 15 turns we had 2 Engineers in the hex doing it but alas-no luck. The conditions are snow and is it only 5% at turn or does it stack up each turn. i have a near the time we started clearing rubble (25 and we might have started on 20 actually) and of course the newest turn 46. Digging in is 10% so half that is 5%-21+ turns seems a bit steep
There is no mention of quality affecting the clearance rate, like there is in laying bridge