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Full text of "Modern Mechanical Engineering Vol-I"

246

HEAVY MACHINERY

casting, more particularly as regards the spacing of the holes for the founda-
tion bolts. As it is the general practice to grout-in bedplates, care should
be taken to see that the top surface of the foundation block is left rough,
so as to allow the grouting material to obtain a grip or bond with the founda-
tion. Where short H-girders are built in, as explained (p. 244.), the level of

Fig, 3.—i, Concrete float.   2, Ground or basement leveL    3, Foundation block.   4,Short steel girders
lilt in.    5, Surface of block left rough for grouting.    6, Air inlet to generator.     7, Space for condenser.

built in.    s,__________

8, Foundation bolt holes.

the concrete should be left at least 2 in. below the top of the girders, in
order to allow the grouting material to obtain a good grip of the girders.
Bedplates.—Before putting the bedplates in position for carrying the
prime mover and generator, care should be taken to see that any heavy parts
of the plant, which are situated underneath, are put in position first, in
order to obviate trouble and difficulty later on. In the case of very large
steam condensers this is essential, but where the weights are not excessive,

Fig. 4.—i, Condenser.  2, Feet of condenser.   3, Wood baulk not necessarily secured to condenser feet.   4. Wood
baulk or steel girder for runway.   5, Steel rollers.   6, Cross batten to tie together supports (3).
and the dimensions reasonable, the condenser may be slid In under the
turbine, after the latter has been erected, and then jacked up or lifted by the
crane, one end at a time, and packed up till in its final position. To do
this, it will probably be necessary to build a suitable cradle, or support of
girders or timber baulks, on which to rest the condenser during this operation.
Let us assume, then, that the condenser and other heavy parts, e.g.
atmospheric exhaust valve and pipes, &c., have been, placed approximately
in position. The turbine bedplate is thea put on the foundations, prefer-