AR, SA&G 5/1/1863 E

Annual Report of the Savannah, Albany & Gulf RR
as of May 1, 1863,
Engineer's Report
Engineer's Report
Engineer’s Department, Sav. A. & Gulf R. R.
Savannah, April 20th, 1863
Major John Screven
   I submit a report from this Department showing the amount of Trestle ridging for which embankment has been substituted, the amount yet to be filled, and the present condition of the work on the Florida Branch from Station No. 12.
   Of the original two miles of Trestle work across the Great Ogeechee River and adjacent swamps, there remains but twenty-three hundred and seventy-five feet, including 850 feet of First Class Trestle across the River, the balance having been filled at a cost of $51,885.00. Of the 13,600 feet originally in the Altamaha Swamp from Jones’ Creek to Doctor Town, 6,900 feet has been filled at a cost of $58,446.55, and a further reduction of 2,200 feet is now being effected, which will leave as permanent 4,425 feet, or a little more than four-fifths of a mile of Bridging, of which, the Lattice Bridge (633 feet) over the main stream forms a part. A contract has also been entered into with Messrs. Walthour & Snyder, to fill during the present year – except short spaces in each – the Trestles across Mount Hope, McIntosh, Gaulding, McCowen’s Creek, and Dunham’s Mill Creek. These Bridges are low and the work will not be very costly. The entire bridging at present on the Road, amounts to 13,351 lineal feet. This will be reduced during this year to 8,224 feet, or three hundred feet over one and a half miles. Many of the shorter Bridges may also be filled entirely or reduced in length, as soon as the Company can obtain the necessary material for building brick Culverts or Abutments. It having been proposed to substitute embankment for the present Trestle work over Morgan Lake, I have in obedience to your instruction, made some examination there for the purpose of ascertaining the difference in the cost of an embankment, and a Lattice or Howe Truss Bridge, resting on brick Piers.
   I find the Lake in the deepest place to be 20 feet at low water; its average depth 16 feet; and its width from bank to bank 525 feet, and that it rises in time of freshets about 11 feet, or within about six feet of the top of the present Trestle work. I have never had an opportunity of ascertaining the rate of the current during high water, but presume it cannot be less than two or three miles an hour. These facts will enable you to form an idea of the pressure to be resisted.
   I submit in a separate statement the result of my estimates, and need not refer to them here further than to notice the fact that a Bridge will cost twenty-five thousand dollars more than an embankment. If therefore the first cost was all we had to be governed by in making a decision, we would of course decide at once upon building an embankment. But I am of the opinion that, whilst an embankment might possibly be made to resist the current of water, it is by no means certain. I think therefore it will be better for the Company to spend twenty-five thousand dollars extra in building a Bridge, than to rely upon the uncertain strength of an embankment.
   Besides, if you were to succeed in building an embankment across the Lake sufficiently strong to resist the pressure of water, you would gain but little more than a choice of evils, as you would then have to leave an opening of near 1000 feet between it and the River which might otherwise be filled.
   This would involve you in the perpetual expense of keeping up a second Class Trestle work, or else in the cost of a Bridge such as would be required over the Lake itself. In the latter case the difference in cost of the two Bridges would amount to but little, as the extra cost of foundation in the Lake would be very nearly counterbalanced by the greater length of the Bridge in the Swamp. For as the bottom of the lake is rock, and not very uneven, the masonry may be built either on crib work or Caissons, at much less expense than foundations under such structures, in so great depth of water usually cost. Another reason why the Lake should not be filled is, that it gives a much better water way than an opening in the swamp would, which is no small consideration.
   The Florida Branch with the exception of a short distance on Section No. 5, is ready for the superstructure. I need not therefore refer to it here, further than to state the cost of each Section of it. The part referred to above as unfinished is in Bee Bay 13 ½ miles from the Junction, where suitable material for building an embankment could not be obtained. It is 1600 feet in length and will have to be temporarily Trestled before the track can be laid. No timber has yet been procured for the superstructure, except a few cross ties and stringers on Section No. 8. The following is the cost of items designated on each Section.
Section No. 1 Clearing, Grubbing and Grading 8,063.39
Bridging 599.77 $8,663.16
" " 2 Clearing, Grubbing and Grading 7,163.16
Bridging 625.60 $7,788.76
" " 3 Clearing, Grubbing and Grading 8,394.12
Bridging 1,531.20 $9,925.32
" " 4 Clearing, Grubbing and Grading 5,214.48
Bridging 1,005.41 $6,219.89
" " 5 Clearing, Grubbing and Grading 6,294.78
Bridging 537.48 $6,832.26
" " 6 Clearing, Grubbing and Grading 10,021.63
Bridging 1,305.63 $11,327.26
" " 7 Clearing, Grubbing and Grading 7,168.74
Bridging 1,072.69 $8,241.43
" " 8 Clearing, Grubbing and Grading 6,934.80
Bridging 716.99
Cross-ties and Stringers 775.00 $8,426.79
" " 9 Clearing, Grubbing and Grading 3,594.17
Bridging 475.69 $4,069.26
Total $71,494.13
Respectfully submitted,
J. T. Stone
Chief Engineer