The Millennium Bridge which crosses the River Thames between St Paul's and Bankside has been shut over the last couple of weeks for it's annual clean and maintenance.
Standing on the north bank and surveying the bridge there seems to be nothing different, apart from the workmen engaged in the task, but if you study the bridge closely you will see an addition.
Dangling from a rope hanging roughly in the middle of the bridge is a large bale of straw.
The reason behind this rather strange addition is Port of London Thames Byelaw, clause 36.2: “When the headroom of an arch or span of a bridge is reduced from its usual limits, but that arch or span is not closed to navigation, the person in control of the bridge must suspend from the centre of that arch or span by day a bundle of straw large enough to be conspicuous and by night a white light.”
The navigable height of the bridge will be temporarily reduced due to the workmen needing to suspend themselves below the walkway to carry out the maintenance.