278 REPORT—1858. 
now proposed for the Nautilus flotilla, the tug and tow-boats are to be con- 
nected together in such a way that the pivot of the tugging post is placed at 
least half the breadth before the stern of the steamer, while the tow-boat had 
a second centre of motion, connected by a rigid spar with the pivot, and 
situated at a point in advance of the cutwater. The tugging post or pivot 
of the tow-boat is made in the form of a timber knee, placed as a bowsprit, 
and provided with two rollers for supporting the connecting hawsers. 
49. There is by this means established between the various barges of a 
river train, the only kind of connexion which admits of sufficient independent 
action for each boat to guide itself in an emergency, and is at the same time 
strong enough to withstand the strain thrown upon them. 
The steering*apparatus is also arranged with the view of independent action ; 
each boat is to be provided with two rudders, one occupying the position of 
the dead-wood aft, and the other oceupying that of the gripe, forward; the 
joint action of these balanced rudders enabling each boat to turn on the 
centre of her length. By using the foremost rudder across the stem, the bow 
of the boat can be made to follow the stern of the steamer without impeding 
the movements of the latter to port or starboard, when turning herself. 
50. The rapidity with which a boat of this description can be manceuvred 
by means of fore-and-aft rudders is easily explained. When the stern rudder 
only is used, the vessel turns upon a pivot situated a short distance forward 
of the stern post; while, if the bow rudder only is used, the boat tends to 
turn on a pivot considerably abaft of the bow. Consequently when both 
rudders are used simultaneously, the common centre of motion will be near 
the middle of the length of the vessel ; on trial, the ‘Assam’ steamer turning 
short round in 15 seconds. 
51. By turning on this centre it is evident that neither bow nor stern will 
have as far to move in turning round as if the pivot were situated near either 
of the extremities, as happens when only one rudder is used. The peculiarity 
of the mode of connexion is, that while the radial spar, forked at one end. 
prevents collision between the bow of the tow and the stern of the tug: the 
distance between them can be at any time increased by means of the hawsers, 
one of which belongs to each vessel, and by hauling up which the crews of 
either boat can slack out or take in, as the occasion may require. 
52. Necessity for greater care as to displacement, weight of hull, and eapa- 
bility for cargo at light draft of water. To be secured by a more correct and 
definite system of contracting for steamers, with specific caleulated quantity, 
by a tabular form of tender.—From inattention to the necessity of obtaining 
correct estimates as to the weight of the vessel and calculations of displace- 
ment, the majority of the steamers sent from this country under terms of 
general capability for the navigation of the Indian rivers, have been found 
to draw a great deal more water than was either specified or contracted for. 
53. With the view of ensuring accuracy in this respect, I have used a form 
of tender for quantities, that was submitted, for the consideration of the 
contractors and shipbuilders with the view of facilitating the calculations of 
the quantities to be inserted in the blank tabular form of tender. 
The quantities given were not intended to be taken as absolutely correct, 
but only as approximations to be verified by the contractors themselves, who 
were requested to state their own quantities with the same form and specific 
detail. : 
The calculation of the displacement, however accurate it may be, only 
gives one of the elements for determining the draft and capability for dead- 
weight cargo; to arrive at anything like certainty with regard to these two 
