II 



It may be remarked that the stresses on the bridge will be 

 reduced in the immediate vicinity of the train. 



[Models of short lengths of the proposed bridge were exhi- 

 bited and experiments conducted, demonstrating its strength, 

 buoyancy, righting moment, resistance to oscillations, steadiness 

 of platform, and the efficiency of all the above mentioned 

 safeguards provided in the bridge against dangers of flooding 

 under all possible conditions. The last mentioned safeguard 

 was demonstrated by means of a model bridge, 9 ft. long, 

 attached to a water tank ; a model of a train was then put into 

 the bridge, and by opening a valve the water rushed into the 

 bridge and shot the train out at the opposite end.] 



The factors of safety in the structure of the bridge throughout 

 are high, the lowest being 7. 



The estimated cost at current prices, including depreciation 

 of plant and Parliamentary and preliminary expenses, is $% 

 million pounds, and the time for completion from date of com- 

 mencement 5^- years. 



Comparing these with the cost and time required to construct 

 a tunnel under the channel, the advantages of a bridge such as 

 the proposed stand out strongly, and would make the relative 

 cost of the bridge compared with the tunnel as about 1 to 5. 



The facilities for constructing the bridge are extraordinary 

 compared with a tunnel, or in fact with any other bridge yet 

 made. A gentleman of vast experience in similar structures 

 states that he would undertake to construct the structural part 

 of the bridge in z\ years with special plant and 1,500 men. 

 The making of the approaches and concrete anchors, and the 

 laying of the sections, may all be advancing at the same time, 

 and the distribution of men may be most advantageously made 

 to ensure expedition. 



Although the foregoing paper was prepared in order to 

 illustrate the feasibility of bridging the North Channel, the 

 proposed submerged bridge is applicable for carrying roads 

 across other channels, straits, gulfs, estuaries, rivers, lakes, etc., 



