Silver Chef is an equipment financing company, and should...

Silver Chef is an equipment financing company, and should therefore be looked at in a similar vein to other financing companies. Those debt ratios can be relatively very high. Nonetheless, SIV has been consistent in maintaining its targeted gearing levels, never having had any problem raising capital through rights issues in the decade or so it has been listed.

Also, gearing is defined as "debt to equity". But what is SIV's true equity? Should it be the stated book value? I would definitely think not - because the value of the company lies in its hidden "economic goodwill", which, given the great history of EPS growth as you've correctly pointed out, would be a multiple of the equity as currently shown on the balance sheet. So the true gearing is much less than the figure quoted.

If rates go up, then SIV's cost of capital would also go up, and like all financing institutions, would likely pass on those increases to its customers. (Higher rates however would have two negative secondary effects on the business, ultimately reducing aggregate market demand for their product, and over time reducing the average earnings multiple that the company enjoys. But the same applies for all businesses.)