There was a quota for the number of passengers allowed on to each trip, and the diminishing number of available places was displayed as the passengers funneled through. As we approached the turnstiles we hoped against hope that we'd make it past the gates within the allowance. I took this snap as the zero came up but we were the wrong side of the barrier. We hadn't made it and we knew that meant another wait, but, it was all good humoured and the process definitely provided a conversational point for our group.