DOCUMENTARY HISTORY OF THE FLORIDA CANAL 55

 Insurance is included as an item of "Operating cost" and hence is not included
in this section, which relates to fixed charges.
 The following additional percentages must be figured on certain classes of
steamers:
 (1) An additional 7 percent on vessels in the sulphur trade, due to the ex-
ceptional corrosive action of the cargo.
 (2) Additional interest, taxes, overhead, and amortization on refrigerating
equipment for combination fruit and passenger steamers, amounting to about 22
percent on a valuation of $275,000 (equipment only). The percentage is high
due to the fact that tbe insulation and refrigerating equipment have a much
shorter life than does the ordinary ship hull and machinery, so that amortization
costs are considerable.
 Note that in the table II, tankers are listed with an amortization charge of 6.67
 percent. This higher charge is due to the corrosive effect of their cargo, which
 eats out the ship in a comparatively short time. Gasoline cargo has by far the
 greatest corrosion rate and the replacement charge on ships engaged exclusively
 in this trade would be about 18 or 19 percent per annum. The 6.67 percent
 charge is an average of all tankers, and is determined by the experience of a
 prominent company over many years of tanker operation.
 Applying the foregoing percentages to the valuations listed in table I the result-
 ing annual, daily, and hourly costs on the various classes of vessels are found to be
 as follows:
 Combination passenger and cargo ships:
 (a) Of 14 knots and over: $2,000,000 at 16 percent equals $320,000 annual
 fixed charge, $876.71 per day, $36.53 per hour.
 (b) Of 12 to 14 knots: $1,500,000 at 16 percent equals $240,000 annual
 fixed charge, $657.53 per day, $27.40 per hour.
 Tankers in the petroleum trade:
 (a) Of 12 knots and over: $1,500,000 at 18.67 percent equals $280,000
 annual fixed charge, $767.12 per day, $31.96 per hour.
 (b) Under 12 knots: $1,200,000 at 18.67 percent equals $224,000 annual
 fixed charge, $613.70 per day, $25.57 per hour.
 Vessels in the sulphur trade:
 (a) All speeds (average 10.5 knots): $900,000 at 22 percent equals $198,000
 annual fixed charge, $542.47 per day, $22.60 per hour.
 General-cargo vessels:
 (a) Coastwise trade, all speeds (average about 10 knots): $900,000 at 15
 percent equals $180.000 annual fixed charge, $369.86 per day,
 $15.41 per hour.
 (b) European trade, all speeds (10-knot average): $700,000 at 15 percent
 equals $105,000 annual fixed charges, $287.67 per day, $11.99 per
 hour.
 Applying the foregoing fixed charges per hour to the number of hours that would
 have been saved in vessel operation by use of the proposed Gulf-Atlantic ship
 canal across north Florida during the calendar year 1929, the resulting savings in
 fixed charges for 1929 amount to $6,419,419.
 A summary analysis of the amount is set forth in the table next succeeding.