268 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



[August, 



in the price of labour in excavations; and when it is considered tbat | points, crossings, and turn-outs, assume a place of greater importance 

 the quantity of excavation on some lines extends to nearly 100,000 [ thau heretofore, and if you think them worthy of a place I will en- 

 yards, the amount then lost was nearly £4000 per mile, or about the | deavour to furnish another paper exclusively devoted to their con- 

 whole cost of the permanent way. This I think is sufficient to show , sideration. 

 that this subject is worthy of attention in all future lines of road. 



Now that railways are being made single lines or partly double ; ' St. Aan't, Sewcaitle.upon.Tyne. O. T. 



THE STEAM EXCAVATING MACHINE. 



We have already had the pleasure of introducing this important 

 machine to the public, and we now avail [ourselves of the opportunity 

 of giving some further account of it. As is well known, it is of Ame- 

 rican invention ; and this individual machine was imported from the 

 United States, after having ben employed on a railway there, for the 

 purpose of testing its capabilities in this country. It is now at work 

 on the Eastern Counties Railway, about 20 miles from London, and is 

 exciting much attention. In its present state, the machine is rather 

 complicated, but it is susceptible of great improvement; and we 

 have no doubt that any machines manufactured in this country will be 

 much simplified. For this purpose it cannot be in better hands, the 

 management of the patent being entrusted,to Mr. John Braithwaite, 

 the .ngineer, whose mechanical attainments are well known to the 

 public, and who is well qualified to turn a machine of this kind to the 

 best account. 



We shall now proceed to describe the performance of the engine, 

 having already given its working details, with an engraving in the 

 Journal, p. 147, No. 68, to which we must refer our readers. The 

 accompanying engraving is a perspective view of the machine when 

 at work, and it will be seen by it, that one man, the engine tender, 

 stands behind, to regulate the performance of the engine, and another 

 man in front to regulate the motion of the scoops and to turn the jib 

 or crane to the right or left, as may be required. By the aid of this 

 jib the scoop is enabled to take a sweep of 30 ft. and clear away 

 obstructions before it to the height of about 14 feet. 



The cubic content of the scoop is 1* yard, and it lifts about li 

 cubic yard, two of which is about a wagon load of 24 cubic yards. 

 If the wagons were brought up as fast as the machine could supply 

 them, it would fill 30 per hour. During the day we inspected the 

 machine, it loaded 26 wagons of 24 cubic yards each within the 

 hour ; and at another performance, it filled 103 cars in 6j hours. Bv 



these trials the duty of the machine appeared to be upon an average 

 20 wagons or 50 yards per hour, or 500 yards per day. This quan- 

 tity does not appear to be more than half the duty of the machines as 

 detailed in a report before us, emanating from a committee of mana- 

 gers of the American Institute, New York, especially appointed to 

 examine the machine. The committee state — 



" The excavator has been employed for three years upon the 

 Western Railroad and other places, and that this test showed an im- 

 mense saving of expense. It is calculated to do the work of 150 men, 

 and will fill cars as fast as they can be presented to receive their 

 loads. Allowing for stoppages, one minute may be given as the 

 average for filling a car of 14 cubic yard. "The interest for the cost 

 of the machine, wear and tear, men's wages, fuel and oil, 134 dollars, 

 (about 21. 16s.), but to cover the contingencies, say 20 dollars." 



There is also another report, showing the daily performance of two 

 machines employed for two months, in almost constant work, at 

 Brooklyn, New York, during which period the two machines worked 

 collectively 881 hours, and excavated and loaded 92,593 cubic yards 

 of earth, equal to 105 cubic yards per hour, or 1080 cubic yards per 

 day. The machines worked during the above period upon an average 

 nearly ten hours per day, which is equal to the working hours of a 

 man. The quantity which one navigator can remove, or "get and 

 fill," in one day, is about 10 cubic yards, or 1 cubic yard per hour ; 

 we have, therefore, the performance of one machine equal to 105 

 men, according to the statements of the American engineers. 



We will now proceed to examine the comparative cost of working 

 by the machine and manual labour. For this purpose we must calcu- 

 late the power of the engine which is called a 10 horse engine, but 

 on account of the high pressure at which the steam is worked, it will 

 be found equal to 34 horse effective piston power. The following are 

 the particulars of the engine : — 



