A new primary proton beamline at TRIUMF for production of spallation neutrons: BL1U is a new primary proton beamline commissioned in TRIUMF’s Meson hall in Fall 2016. The beamline ends in a target made of tungsten and provides spallation neutrons for fundamental neutron research to the Ultracold Neutron Facility. BL1U is unique in that it shares the proton beam provided by TRIUMF’s 520 MeV cyclotron with BL1A, the other primary beamline in the Meson hall. This is facilitated by a special, very fast-kicker magnet which ramps its field on-and-off during the 100 microsecond gap between two proton pulses, and thus diverts single proton pulses out of BL1A into BL1U. Since the Centre for Material and Molecular Science instruments rely on BL1A proton beam, this innovative beam sharing enables the simultaneous operation of both facilities.