QUESTIONS RELATING TO STEAMERS.

Q.-You have a fresh crew, what would you teach them first? A. To drive the steam winches.

Q.-In what position must the man stand who is driving the winches ?

A.—His hand must be near, or on, the throttle-valve, his right hand on the slide-valve lever, and one foot near the brake.

Q.

-When leaving winches under steam what precaution would

you take?

A.-Shut the throttle-valve and open the drain cocks in the bottom of the cylinder, to allow the condensed steam to escape, otherwise, when starting again, I might split the cylinder bottom. Q.-How should a steamer's ventilators be trimmed?

A.-So that the weather one for the time being shall be the uptake (see page 31).

Q.-What are water ballast tanks?

A. They are tanks built inside the vessel, and frequently form a portion of the vessel itself; they are filled with water which serves as ballast.

Q.-How are they filled?

A.-By opening the sea cocks, which allows the sea water to flow into them.

Q. How are they emptied?

A.-By the donkey ballast pump.

Q.-Describe the latest form of construction as regards the inlet for water of ballast tanks.

A. In the newest construction of ballast tanks there is only one inlet for the water, this inlet being through a valve box placed in the engine room, and all the ballast tank valves lead into this box, which is well marked, viz. :—fore hold, main hold, after hold, &c. No water, therefore, can pass into the tank unless it comes through this valve box in the engine room; each tank having a separate pipe leading from it to the valve box. These pipes are also connected by valves leading to the donkey engine, and are used to pump the water out of the tank. There are also sounding pipes fitted to the tanks which ought to be frequently used when the ship is full of cargo.

Q.-Who has the control of the ballast tank?

A. The engineer.

Q.-What precaution would you take when filling the tanks, and why?

A.-Take great care that they are quite full, for if not completely filled it causes the ship to roll heavily, and brings great strain upon the tank top.

Q.-How do you know when the tank is quite full?

A.-Keep the sounding pipe cover off, then when the water tank is nearly full the water will commence to fly several feet above the deck, but will gradually subside till the sounding pipe is full to level of the deck, when the tank will be quite full.

Q.-What are the advantages of water ballast tanks?

A.-When moving a ship from one port to another in ballast it saves the expense of buying, loading, and discharging ordinary ballast, and also the loss through detention in both operations; because opening the water ballast cocks allows the water to run in as the ship goes along, and as she is approaching her port she begins to discharge it through her donkey ballast pump.

Q. What disadvantage has water ballast tanks?

A.-When the ship is loaded and the tanks are empty her cargo is too high, thereby making her crank.

Q.-What are water-tight bulk-heads, and what are they for? A.-They are strong iron partitions built inside the ship extending from side to side, and from the under part of the upper deck to the bottom of the hold. By this means the hold of a vessel is divided into several water-tight compartments, so that in case of leakage in any one of them the water is confined to that compartment.

Q.-Describe any arrangement of sluices you know of?

A.-The water ballast tanks of steamers are seldom carried into the sides of the vessel, consequently between the outside of the tanks and the sides of the ship there remains a space of about eighteen inches in width, and extending fore-and-aft of the tanks; this space is constructed as a water way, and in which are the sluices. This mode of construction is intended to afford means of getting the water to the engine room if the ship is damaged or holed above the tank tops.

Q. Where are the sluices placed?

A.-The sluices are placed at the after end of the tank sides in the fore holds, and at the fore part in after the holds, and are situated at every water-tight bulk-head fore-and-aft on both sides of the ship.

Q.-What are the sluice valves?

A. They are sliding doors or valves on the lower parts of the water-tight bulk-heads, which, on being opened, allow the water to be drained from one compartment to another if required.

Q. How are the valves worked?

A.-The valves are connected to vertical rods that lead to the upper deck immediately above the sluices and by fixing a key upon the heads of these rods and turning them the valves are opened and shut. The rods are covered by brass water-tight caps on the upper deck, and are marked so that it is seen when the valves are open or shut, and that duty devolves upon the carpenter of the vessel.

There ought to be a sounding pipe at every sluice, so that the holds can be sounded every four hours. The water ways to the sluices should be frequently cleared out, as they are the only means, excepting the hand pump, of getting clear of any water in the hold when the ship is full of cargo.

Q.-Explain the action of the rudder of a screw ship with regard to speed, and a large or small angle of rudder?

A. The great thing to remember is this, that when a ship is answering her helm it is the stern being thrown round by the pressure of water on the rudder which alters her course, and that it is the head which is governed by the stern and not the stern by the head; so much is this the case in screw ships able to give a large angle of helm, that if the helm be first put hard over and the engines started ahead the ship will turn two or three points before gathering way.

As a general rule it may be stated that screw ships turn on a point one-third before their centre; therefore, in avoiding collision, when nearing the danger, steer so that your bow may go clear; having done this, as the point on which your ship pivots passes reverse the helm, and by so doing endeavour to throw your stern clear. The more helm given the smaller will be the diameter of the circle made; the more speed used with the same helm the quicker will you turn though describing a larger circle.

Q.-What is meant by a right-handed screw propeller?

A.-Right-handed propellers are those which turn the same way as the hands of a clock, the observer being placed abaft the clock whose face is turned aft. They revolve from port to starboard of the ship during the upper part of its revolution while the ship is moving ahead.

Q. What is meant by a left-handed screw propeller?

A.-A left-handed propeller is one which revolves from starboard to port of the ship during the upper part of its revolution when forcing the vessel ahead.

Q.-With helm amidship and vessel going full speed ahead with a right-handed screw propeller, on which side of her course will the ship's head go?

A. A right-handed screw propeller tends to send a ship to the port side of her course, the effect being as if she carried a starboard helm.

Q.-What effect has a right-handed screw propeller on a ship with helm amidship going full speed astern?

A. To throw her to starboard of her course; that is, a steamer's stern under these circumstances will turn to port.

Q.-What effect has a left-handed screw propeller upon a ship going ahead?

A. To throw her to starboard of her course.

Q.-How will a steamer's stern turn when you reverse the engines, with a left-handed screw propeller?

A.-It will turn to starboard.

Q.-Can a steamer be steered to go straight astern?

A.-A steamer cannot be steered to go straight astern, no matter what precautions are taken, as her propeller, in the end, if unaffected by tide or current, will eventually put her athwart, and, if at sea, turn her completely round. With a right-handed propeller she will come round to starboard all the time, and the reverse with a left-handed propeller.

Q.-Coming astern you want a steamer with a right-handed propeller to come to starboard with her bow, how will you put the rudder?

A. Hard-a-starboard with a right-handed propeller.

Q.—With a left-handed propeller, coming astern, you want her head to come to port, how will you put the rudder? A. Hard-a-port.

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Q.-You are in narrow waters, your vessel has more way on her than will pass the object and too much to stop her before reaching it, what precaution would you take in respect to the

helm ?

A. With a right-handed propeller I should take great care not to give the vessel too much port helm, because if she will not clear the object by going ahead full speed astern will cause her to fly to starboard and make worse of it. With a left-handed propeller a ship should be very carefully watched in giving her starboard helm, for, if she will not clear by going ahead, full speed astern will make matters worse.

NOTE.-If you wish to cant to port with a right-handed propeller it cannot be done by going astern, as it matters not which way the helm is put, if the vessel have little way on her she will go to starboard, and the reverse of this will occur with a left-handed propeller; if unaffected by the tide, the vessel will pay little attention to the rudder at first, but the rudder must be used to help her round directly she begins to get sternway; or, in other words, the rudder is of no use to a screw steamer till she gets sternway upon her, for she will begin to cant before the rudder becomes useful. In these remarks it is supposed that the vessel is uninfluenced by wind or tide, as either of these may produce a contrary effect. Wind or tide will cant steamers, especially light ships, against their propellers, and it must be borne in mind that whichever way they first begin to cant they will continue to do so to the end; that is, when going astern.

Q.-You are in a screw steamer at sea with a right-handed propeller, which is the quickest way in turning her short round? A.-She turns quickest with her port helm, thus:- Going full speed ahead, put the helm hard-a-port, and when on full swing of port helm, stop the engines, and when she loses way bring the engines full speed astern, and reverse the helm by putting it hard-a-starboard, and she will in this way come quicker round than she will by going ahead at full speed with either helm.

Q.-You are in a narrow channel in a steamer with a righthanded propeller, there is a strong tide in mid-channel and slack water on your port side, how would you turn her round?

A.-Put the helm a-starboard to bring her into the port side of the channel; when all clear put the helm hard-a-port, full speed ahead, which will bring her port bow into the tide; stop her, change the helm, full speed astern, to keep her stern in slack water; then hard-a-port and full speed ahead, until she comes round.

Q.-Coming down a river before the tide and it becomes necessary to bring your vessel to a sudden stop, how will you proceed?

A. Give her a slight sheer to port and bring her full speed astern, then the ship will straighten herself end on to the tide; when she has lost her way, drop your anchor and swing round. Q.-A screw steamer under the spouts, or against a wharf, what precautions would you adopt?

A. Have fenders over the side to prevent chafe. bow and quarter rope to secure her.

Have a

Q.-You are lying alongside a wharf, wind blowing hard, and

the vessel is ranging about, what would you do?

A.-Get springs from head and stern.

Q.-In getting under weigh, what should be seen to before starting the engines?

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