  The Double Triple Bend Achromat (DTBA) lattice~\cite{DTBAipac16} is a novel
lattice design for a next generation 3 GeV Synchrotron Light Source. Starting
from a modification of the Hybrid Multi Bend Achromat (HMBA)
lattice~\cite{ESRF} developed at ESRF and inspired by the Double-Double Bend
Achromat (DDBA) lattice~\cite{Diamond1, Diamond2} developed at Diamond, DTBA
combines the advantages of both cells. The typical MBA lattice cells have one
straight section dedicated to an insertion device, whereas this new cell layout
has two such drifts, thus increasing the fraction of available space for the
installation of insertion devices. The DTBA lattice achieves an emittance of
$\sim\mathrm{132~pm}$, a dynamic aperture of $\mathrm{\sim\pm10\pm1~mm}$
(calculated at the injection point), an injection efficiency of
$\mathrm{\sim\mathrm88\pm5\%}$ and a lifetime of $\mathrm{1.4\pm0.2~h}$ with
errors. The characteristics of DTBA, the methodology and results of the linear
and non-linear optics optimisations, with and without the presence of errors,
are presented in detail.
