G.T. was reputed to be a showman, but no accountant.
The park has often suffered from cash flow issues over the years, it has always been weather dependant, suffered from the move to continental travel, and the general shifts in popularity of the resort...it hasn't always been grotty inshore!
Valhalla was rumoured to be well over budget, the boss insisted on changes to the design, and tried to cram too much into the space available, so corners, quite literally, had to be cut.
In the longer term, it wasn't the interest payments on the capital investment that made things so difficult financially, but the horrendous running costs of the ride.
Popular, a shadow of its former self, and a financial millstone to the park in the days of all day wristbands.