"Its boundless compass, including as it does, every state and non-state institution, coupled with the absence of any built-in time parameters, does not fit comfortable or practically within the single inquiry model in which it currently resides.
"Nor is delivery on the limitless extent of all the aspirations in its terms of reference possible in any cohesive or comprehensive manner.
"I have recommended in my report to the Home Secretary that my departure provides a timely opportunity to undertake a complete review of the Inquiry in its present form, with a view to remodelling it and recalibrating its emphasis more towards current events and thus focussing major attention on the present and future protection of children."
She also questioned the inexperienced staff tasked with running the inquiry.
"None of the secretariat or senior management team had previous experience of running an inquiry of this nature," she said.
"I felt as chair handicapped by not being given a free hand to recruit staff of the type that I judged to be essential."
The final straw for her was the delay of public hearings, which had already been set back several times, to next year.
"That was hugely concerning. It also caused justifiable criticism and a loss of confidence, for which I, as chair, had to take ultimate responsibility."
After her resignation, Dame Lowell came under scrutiny for her lack of understanding of English law, her long periods of leave and her generous pay.
Her salary of $640,000 plus $200,000 in entitlements made her one of Britain's highest-paid public servants.
It was revealed that she had spent 30 days on leave in her first year in the job, and 44 days in Australia, where she held just two meetings with members of a child abuse inquiry there.
Dame Lowell defended her handling of the inquiry.
"I can assure the members that over the 16 months I have worked as chair, there has never been a time when the Inquiry and its objectives did not dominate my life."
"I made a firm commitment to undertake it and was determined to see it through to its conclusion. I am disappointed that that this has not been possible.
"It was never easy operating in an environment in which I had no familiar networks and there were times when it seemed a very lonely mission.
"However, I am pleased I was able to set it on its way. Ultimately, however, I had to face a situation I could not solve and which would continue unless challenged.
"I resigned to make that challenge occur."
The inquiry was established in 2014 following allegations of a paedophile ring operating within Westminister in the 1980s, and is investigating whether public institutions failed in their duty of care to protect children from child abuse.
