There used to be what was called a 'polar' departure from Heathrow; can't remember much detail except that it was pre B747, and was specifically for slow climbers and instead of a right turn towards Beacon Hill fan marker, they used to go left and circle round across final approach direct Garston. I think this procedure may have been dropped when Bovingdon VOR came on line, but maybe if Heathrow Director reads this, he may be able to supply other details.