DESIGN AND CONSTRUCTION OF PASSENGER STEAMERS. 281 



These figures represent smooth-water powers plus 10 per cent for the 25 knotters and 

 plus 1 5 per cent for the 30 knotters. The dimensions dependent on length follow average 

 merchant practice, except that the beam on the 1,000 footer has been limited to suit the 

 Panama Canal lock dimensions to 102 feet. 



It is clear from this table that a Mauretania at 30 knots would bear out Sir William 

 White when he says that no greater length is necessary. 



Destroyers attain a speed-length ratio of 2.00, but it cannot be claimed that they attain 

 it with comfort and safety except in quite moderate weather. European cross-channel steam- 

 ers obtain a ratio of 1.50 with greater safety and comfort than destroyers; where the line 

 must be drawn for the North Atlantic is our problem. The ships listed above cover a range 

 of from 1.225 for the 600 footer to 0.95 for the 1,000 footer at 30 knots. The Mauretania's 

 figure is 0.95. From this it is submitted that the 750-foot ship of 30 knots as proposed 

 is practicable, providing the fore ends of the ship and of the midship deck erections are 

 especially designed and strengthened, with, a view to avoiding deck damage in weather not 

 otherwise severe enough to make slowing up necessary. All fittings and deck openings be- 

 fore the bridge would need to be of special design. 



The table above for varying lengths is calculated on a somewhat different basis from that 

 given on page 279, somewhat different proportions, coefficients, and powers. The two 

 tables were prepared from different angles but remain substantially comparable. 



The question of powers to be expected if very fast liners of warship types were to be 

 adopted is interesting and is another angle of the question that should be investigated. The 

 table of powers varying with length and speed given above covers merchant types developed 

 from current liner practice; the following covers some of the ground as indicated to us by 

 warship practice. 



The proportions and speed both render large and high deck houses out of the question; 

 the passage would be short and promenades would have to be arranged on the quarter deck 

 aft and on one deck amidships well protected from spray. 



Fast yachts have already been built on destroyer lines, so that liners on cruiser lines are 

 only a logical step and one that has been discussed before. 



The speed has been taken at a 20 per cent advance on previous general practice ; the time 

 on a 3,000-mile run in moderate weather is also given. In the powers given a 10 per cent 

 margin for sea speed is allowed over a measured mile performance. The bunkers work out 

 at quite large figures. It can be assumed that oil fuel is obligatory, coal handling would be 

 well-nigh impossible both on board and alongside. These bunker capacities are high, but 

 not impractical. Taking only first-class passengers and allowing 1 J^ per foot of length, we 

 get the numbers given in the table. The longitudinal coefficient is 0.58 and the mid area 

 0.90 for all lengths. 



It is seen that the increase from 29 to 36j4 knots cuts one day off the voyage. As 



