33 CFR §117.23

1. (a)When the District Commander deems it necessary for reasons of safety of navigation, the District Commander may require the installation and operation or a radiotelephone on or near a drawbridge.
2. (b)The District Commander gives written notice of the proposed requirement to the bridge owner.
3. (c)All comments the owner wishes to submit shall be submitted to the District Commander within 30 days of receipt of the notice under paragraph (b) of this section.
4. (d)If, upon consideration of the comments received, the District Commander determines that a radiotelephone is necessary, the District Commander notifies the bridge owner that a radiotelephone shall be installed and gives a reasonable time, not to exceed six months, to install the radiotelephone and commence operation.