  In this work, based on the Fredkin spin chain, we introduce a family of
spin-$1/2$ many-body Hamiltonians with a three-site interaction featuring a
fragmented Hilbert space with coexisting quantum many-body scars. The
fragmentation results from an emergent kinetic constraint resembling the
conserved spin configuration in the 1D Fermi-Hubbard model in the infinite
onsite repulsion limit. To demonstrate the many-body scars, we construct an
exact eigenstate that is in the middle of the spectrum within each fractured
sub-sector displaying either logarithmic or area-law entanglement entropy. The
interplay between fragmentation and scarring leads to rich tunable non-ergodic
dynamics by quenching different initial states that is shown through large
scale matrix product state simulations. In addition, we provide a Floquet
quantum circuit that displays non-ergodic dynamics as a result of sharing the
same fragmentation structure and scarring as the Hamiltonian.
