A dual motor hydraulic hybrid transmission (1, 1'), comprising: a power source; a hydraulic circuit comprising: a hydraulic pump drivingly engaged or selectively drivingly engaged with the power source; a first hydraulic displacement unit in fluid communication with the hydraulic pump; and a second hydraulic displacement unit in fluid communication with the hydraulic pump; a hydraulic accumulator assembly comprising a high pressure accumulator and a low pressure accumulator, the hydraulic accumulator assembly in fluid communication with the hydraulic circuit; one or more control valves (PA, PB, VHP, VLP); and an output shaft; wherein the first hydraulic displacement unit is drivingly engaged or selectively drivingly engaged with the output shaft, and wherein the second hydraulic displacement unit is drivingly engaged or selectively drivingly engaged with the output shaft; and wherein the control valves (PA, PB, VHP, VLP) are configured to selectively: fluidly connect the hydraulic pump to the first hydraulic displacement unit while fluidly disconnecting the hydraulic pump from the second hydraulic displacement unit; and, simultaneously, fluidly connect the hydraulic accumulator assembly to the second hydraulic displacement unit while fluidly disconnecting the hydraulic accumulator assembly from first hydraulic displacement unit; characterized in that the control valves (PA, PB, VHP, VLP) are further configured to selectively: fluidly connect the hydraulic pump to the second hydraulic displacement unit while fluidly disconnecting the hydraulic pump from the first hydraulic displacement unit; and, simultaneously, fluidly connect the hydraulic accumulator assembly to the first hydraulic displacement unit while fluidly disconnecting the hydraulic accumulator assembly from second hydraulic displacement unit. a power source; a hydraulic circuit comprising: a hydraulic pump drivingly engaged or selectively drivingly engaged with the power source; a first hydraulic displacement unit in fluid communication with the hydraulic pump; and a second hydraulic displacement unit in fluid communication with the hydraulic pump; a hydraulic pump drivingly engaged or selectively drivingly engaged with the power source; a first hydraulic displacement unit in fluid communication with the hydraulic pump; and a second hydraulic displacement unit in fluid communication with the hydraulic pump; a hydraulic accumulator assembly comprising a high pressure accumulator and a low pressure accumulator, the hydraulic accumulator assembly in fluid communication with the hydraulic circuit; one or more control valves (PA, PB, VHP, VLP); and an output shaft; wherein the first hydraulic displacement unit is drivingly engaged or selectively drivingly engaged with the output shaft, and wherein the second hydraulic displacement unit is drivingly engaged or selectively drivingly engaged with the output shaft; and wherein the control valves (PA, PB, VHP, VLP) are configured to selectively: fluidly connect the hydraulic pump to the first hydraulic displacement unit while fluidly disconnecting the hydraulic pump from the second hydraulic displacement unit; and, simultaneously, fluidly connect the hydraulic accumulator assembly to the second hydraulic displacement unit while fluidly disconnecting the hydraulic accumulator assembly from first hydraulic displacement unit; characterized in that fluidly connect the hydraulic pump to the first hydraulic displacement unit while fluidly disconnecting the hydraulic pump from the second hydraulic displacement unit; and, simultaneously, fluidly connect the hydraulic accumulator assembly to the second hydraulic displacement unit while fluidly disconnecting the hydraulic accumulator assembly from first hydraulic displacement unit; the control valves (PA, PB, VHP, VLP) are further configured to selectively: fluidly connect the hydraulic pump to the second hydraulic displacement unit while fluidly disconnecting the hydraulic pump from the first hydraulic displacement unit; and, simultaneously, fluidly connect the hydraulic accumulator assembly to the first hydraulic displacement unit while fluidly disconnecting the hydraulic accumulator assembly from second hydraulic displacement unit. fluidly connect the hydraulic pump to the second hydraulic displacement unit while fluidly disconnecting the hydraulic pump from the first hydraulic displacement unit; and, simultaneously, fluidly connect the hydraulic accumulator assembly to the first hydraulic displacement unit while fluidly disconnecting the hydraulic accumulator assembly from second hydraulic displacement unit.