89 G
THEORY AND PRACTICE OF ENGINEERING.
Book II.
The expense of overlooking workmen consists in the payment of foremen and clerks, whodo not labour, but keep the account of the various materials and time.
Gauthey in his valuable work, “ Trait6 de la Construction des Ponts," has given us thefollowing data upon which we may form our calculations, and it is to be regretted we havenot had similar experiments made upon the labours of English workmen.
Ground Work: under this title is comprehended the digging and removal of earth, layingthe turf, ballasting and dredging, &c. Excepting charges made for cutting turf, the onlyexpense for these works is the labour ; they are generally performed by a lower grade ofworkmen, and in companies. The price required is given in hours; the price of an hourdepends upon the value of a day’s work, and the number of hours or effective hours itcontains, which is usually ten.
Excavating. The time employed in digging depends upon the nature of the soil; andthe mean results, which serve as comparisons, are as follows: —
Hour.- 0-60
or 35‘3 cubic feet En-
-
-
-
- 0-90
glish, or one and a
- .
-
-
- 1-50
third cube yards.
-
-
- 2*00
-
-
-
- 2*50
Removal of Earth comprises loading and unloading: when the barrows or carts cannotapproach close to the workmen, it is necessary to throw the earth with a shovel, eitherhorizontally or vertically on scaffolds raised 2 metres over each other.
For throwing a cube metre (or 1£ cube yards English ) with a shovel :
Parts of anHour.
Vegetable earth, loam, or sand - • - - - - 0 65
Hard earth, clay, and tufa - - - - - - -0-75
Mud - - - - - - - - - 0-80
When the removal takes place by barrows, it is executed by relays; if the ground islevel, or slightly inclined, each relay is 30 metres in length, and 20 when the inclination is1 in 12A.
{
{
Vegetable earth, loam, and sandClay, stony ground, and tufaMud -
Vegetable earth and loamClay, stony earth, sand, mud
OGO
0-70
0-75
0*45
0*55
The specific gravity of vegetable earth and loam is 1 *5, and each barrow contains 0 04cube metres.
It is most advantageous to use carts when the distance is from 150 to 200 metres:when this distance is not very great, trucks drawn by men are preferred ; some of a veryingenious construction, used at the bridge of Neuilly , contained 0'2 cube metres of loam,and were drawn by three men.
Parts of anHour.
f Vegetable earth, loam, and sand - - 0-63
A cube metre drawn by trucks < Clay, hard stony earth - - - - 0 73
[Mud ------ 0*78
For the removal, each cube metro of earth is estimated in the following manner :supposing five trucks employed, drawn by three men, and three workmen employed toload,
‘ Vegetable earth, loam, and sand
Parts of anHour.
- 0*042
Clay, hard stony earth, and tufa
-
- 0*049
Mud -
-
- 0-052
Vegetable earth and loam
- 0*060
Clay, stony earth, sand and mud
-
- 0*070
Time of unloading
-
- 0*030
taining 0-2 cube inches
Time to go a distance of an ihundred metres, and return, Jthe ground being level, or]nearly 110 yards English |
If the road is bad, or the rise and fall considerable, some additional allowance must bemade. When carts drawn by horses are used, it is advantageous to have as many men toload as is practicable ; our calculations suppose three employed for that purpose.
Parts of anHour.
To load a cube metre in a cart
{
Vegetable earth, loam, and sandClay, stony earth, &c. -Mud -
0-65
0-75
0-80