I am at Melbourne/ Highfield Rd allotments, also have friends at Baddow with an allotment. I know of someone trying to get an allotment on Avenues where I looked to get one but as share several allotments with my father, the Melbourne/ Highfield Rd ones were between our homes. Sharing comes in handy when you go on holiday, always someone to water, pick and freeze the crops.
In the summer my son and I have on a couple of occasions spent time cycling stopping off at the allotments in Chelmsford to have a look. Unfortunately the older he is getting the wiser he is becoming. When I say would you like to go on a bike ride, he wants to know where and how far and checks that we will not be going via any allotments including my own. Its a pity you cannot get the x-box to run on the allotment I would not have any trouble getting him down there then and I could spend even more time there myself.
Where is your allotment in Danbury EJ, I don't think I will get my son to cycle that far, but do sometimes pass through in the car.