Navy Shiphandler's Guide Flashcards
List your controllable and uncontrollable forces
Controllable
- Lines
- Anchors
- Tugs
- Engines
- Rudders
Uncontrollable
- Wind
- Current
- Bernoulli Principle
A ship using half its power can make up about 80% of its max speed. Why?
Resistance of the sea on the hull increases sharply with speed increase. The ship will accelerate to where the thrust generated will balance with the resistance created.
Which way do the screws rotate on a CG? What effects does that have for MOB? Is this normal for twin screw ships?
CGs turn inboard. It pushes things away from the ship when they approach the screws from the surface. Most ships rotate outboard.
How does a rudder work to turn the ship? Assume a RIGHT turn.
- Moves the stern of the ship in the opposite direction of where the ship wants to turn.
- to turn right, the rudder swings right
- this creates a pressure differential on the rudder, with a higher pressure to STBD and reduced pressure to PORT
- the resulting force moves the stern to PORT
- creates a drift angle that creates a pressure on the port bow of the ship
-combination of pressure on the bow and stern cause the ship to turn to STBD.
Why is a rudder much less effective when backing?
The rudder works by absorbing and deflecting the proper wash. The wash is absent when backing.
As the rudder angle increases, the turning force ____ and drag ____.
TF–decreases
Drag–increases
Define tactical diameter
The lateral transfer a ship will travel when executing a 180 degree turn
Define advance
The forward transfer a ship will move when executing a 90 degree turn
Where is the pivot point if:
1) moving ahead
2) backing
3) DIW with tug pushing the pow
4) ship moving ahead with a spring line to the pier
5) ship going ahead against an anchor led through bow chock
1) 1/3 of the way toward aft
2) aft-most point
3) 2/3 of the way toward aft
4) close to the bow
5) directly on the bow
When would you utilize a spring line from the bow to the after-ish part of the pier for maneuvering? Which line would this be?
When you desire to push the stern from the pier for an underway without tugs. Line 2
What is the main factor that drives the placement of the pivot point?
It will move towards the resistance against the ship. Ship is moving forward–water is resisting the bow’s movement–pivot point moves forward.
What is the difference between an APU and a thruster?
APUs are train-able
Thrusters are stationary
How would you use an APU?
Oppose the APU to the ship’s engines, which would push the ship sideways into a slip
How would you use a bow thruster?
Used to control the direction of the bow balance this with an engine twist to push the ship sideways into a slip
How are lines numbered on the CRUDES?
1-6 from bow to aft ON THE SHIP
What are the names of the lines on the ship?
1) bow line
2) after bow spring line
3) fwd bow spring line
4) after quarter spring line
5) fwd quarter spring line
6) stern line
How effective are APUs and thrusters as the ship gains speed?
Less effective
On a CVN, what’s the rule of current and wind?
20 kts of wind = 1 kt of current
On a CRUDES, what’s the rule of current and wind?
30 kts of wind = 1 kt of current
What are 2 methods of understanding wind speed OFF SHIP when pulling into port?
Wind flags
Current ripples pushing past buoys
On a CRUDES, how will the ship tend when being pushed by a BEAM wind? Why?
Bow will be pushed away from the wind.
More surface area in the FWD half of the ship for wind to influence.
Which is easier to handle–a current coming from AHEAD of or AFT of the ship? Why?
Ahead. It increases the wash over the rudder, this increasing rudder effectiveness.
How do anchored ships tend to move when it’s windy?
Swing over to face INTO the wind
What is Bernoulli’s Principle? What does it mean?
It’s a conservation principle:
“The sum of the energy of velocity, the energy of pressure, and the potential energy of elevation remains constant.”
If you increase velocity of the fluid hitting your bow, it will create a decrease in pressure on the other side of the bow, which means your bow will tend towards an area of lower pressure.
Apply Bernoulli’s Principle to UNREP.
- Fluid speed increases when fluid is forced through a narrow/restricted area.
- The increased fluid speed therefore decreases fluid pressure
- This is called the VENTURI EFFECT.
- When your ship is next to an UNREP ship, the fluid between the ships increases speed as it travels from between the bows to between the sterns.
- This causes a length-wise decrease in pressure where the pressure between the bows of the ships remains greater than the pressure located at the sterns of both ships
- Overall, this causes a reduction of pressure along the inboard sides of both ships
- This causes the ships to want to get sucked towards each other (don’t forget water initial water pressure did not decrease along the outsides of the ships, which means it’s at a higher overall pressure on the outsides of the ships, which causes the ships to want to tend towards the direction between the two ships
How does the VENTURI EFFECT change when speed increases?
The effects increase.
How does the VENTURI EFFECT change when the ships move closer together?
Gets stronger (further reducing the area increases the speed which decreases pressure in between the ships even further)
You’re in shallow water. Is your rudder more or less effective?
Less
You’re still in shallow water. Why does SQUAT happen (BERNOULLI)?
Shallow water means you’ve restricted the area between the ground and your ship. Therefore if you increase the speed, the pressure will drop from its highest point at the bow to a low point at the stern. That causes your stern to sink.
What’s the difference between giving a STANDARD/FULL rudder order and a HARD rudder order? Why?
STANDARD/FULL are prefaced with a direction, and are said second. “LEFT Standard Rudder.”
HARD is stated first to ensure the Bridge Team understands the urgency and necessity of expedient action. “HARD LEFT Rudder!”
What should RPM be if you need to do an EMERGENCY increase in backing/ahead bell?
999
What is the equation for the Invisible Distance under the bow?
I = (B*D) / (A-B)
A = Height of Eye (where you are) B = Height of Bow D = Distance from Bridge to Bow I = Invisible Distance
Should you ever plan an evolution where large backing bells or full maneuvers are required? Why or why not?
Fuck no. That means if there’s a miscalculation or casualty, there’s very little you can do to correct it with engines and rudder.
What is a Bitt?
Pair of short steel posts or horns onboard the ship used to secure lines
What’s the Bullnose?
Closed chock at the bow of the vessel
What’s the Camel?
Float used as a fender between 2 ships, or a ship and a pier.
What is a Breasting Float?
Same as a Camel
What’s a chock?
The metal fitting through which hawsers and lines are passed prior to being wrapped around the bollard.
What is a Cleat?
The anvil-shaped fitting used for securing or belaying lines
What is a Dolphin?
A cluster or clump of piles used for mooring. A single pile or a bollard on a pier is sometimes called a dolphin.
What is a Piling?
Wooden, concrete, or metal poles driven into the river or sea bottom for support or protection of piers or wharves
What is a Bollard?
Steel or iron post on a dock, pier, or wharf used in securing a ship’s lines
In the absence of a significant current, what angle should your approach be made to the pier heading?
Roughly 15-20 degrees towards the pier (aka point the bow at the pier)
How would you use Quickwater to visualize the way of the ship while backing?
Backing bells cause quickwater swirling patterns at the aft end of the ship.
DIW? Quickwater reaches amidship.
2 knots sternway? Quickwater begins to move ahead.
3 Knots sternway? Quickwater moves with the ship (i.e. in the direction of your sternway)
What is the deepest water levels that ships normally will not have enough anchor chain to anchor out?
15 fathoms
If anchoring in deeper water, how should you pay out the anchor?
Slowly until the anchor is near the bottom – then you can let go. Otherwise, the speed and momentum may be too much for the anchor brake to handle.
If anchoring in deeper water, should you prefer to pay out more anchor chain or set a 2nd anchor?
Set a second anchor to reduce wear/forces on your anchor brake.
You’re anchoring in an unprotected harbor and your bow moves around a lot. What can you do to dampen bow movement?
- Use greater scope of chain
OR - Put a 2nd anchor underfoot
OR - Drop a 2nd anchor with minimum scope to dampen theback/forth motion of the bow
IF NEEDED - Pick up the 2nd anchor, then drop it when the ship is at maximum swing, then equalize tension between the two anchor chains
Give 2 examples of when you might use your rudder while you’re anchored?
- A strong current keeps sheering your ship to one side and then to the other —- using your rudder can move your ship to one side of the sheer and hold her there.
- Another ship near you is dragging anchor and headed your way. Your rudder may swing you out of the way.
Describe 2 ways to use an anchor to slow the ship if in extremis.
- Drop the anchor ONLY to the short stay so that the anchor drags over the bottom (but doesn’t dig in)
- Drop the anchor and pay out chain at reduced rates to slow the ship
Why is it difficult to twist a DDG’s bow into the wind?
More sail area up forward
If you are stuck in a position where the bow of your DDG just won’t twist into the wind and you’re just drifting with the current down a channel, what can you do?
Drop the anchor at SHORT STAY. This will bring your bow smartly into the wind
Describe how to use the poor man’s tug.
- The anchor on the side away from the berth should be made ready for letting go
- Bring your DDG in at a wider angle to the pier
- When your bow is 100 yards from the its intended final position, DROP ANCHOR and veer chain as necessary to keep the bow under control
- This also permits you to use stronger engines b/c the anchor is retarding the ship’s way
- Utilize the anchor as a bow tug and engines to control stern as you land onto the pier
- Anchor is left on the bottom until you get underway again
- Moor with a detachable link positioned for slipping the anchor in case the anchor is stuck
What is an advantage and a disadvantage of mooring to a Mooring Buoy?
ADV Mooring buoy is anchored stronger than you can achieve with your anchor
DIS Hard af to execute, and dangerous as hell.
What are the steps of anchoring (anchor specific, not Shiphandling)?
Make the anchor ready for letting go
Dip the anchor
Walk the anchor to the water’s edge, or to fifteen fathoms on deck, etc.
Veer to (# fathoms on deck)
Let go the anchor.
Heave around to Short Stay (walk the chain in on the windless)
These are not in order*****
What do the following mean? Anchor at the short stay, anchor is up and down, anchor is breaking ground, anchor’s aweigh, anchor in sight, anchor is clear (or foul).
Short Stay–Anchor is nearly up and down, and just about to break out
Breaking Ground–Anchor is about ready to break out. Can be observed because the chain is nearly vertical and is jerked as the anchor breaks ground.
Up and Down–Anchor has broken ground but is still resting on the bottom
Aweigh– Anchor is clear of the bottom and the ship is underway
In Sight– Anchor detail can see the anchor
Clear (or Foul)–Anchor is clean or there’s a some of bottom stuff on it, like a cable or a lot of debris
How long is a SHOT of chain, in fathoms?
15 fathoms
How many feet is a fathom?
6 feet
How many total feet in a SHOT of chain?
90 feet
Discuss the color scheme for anchor chains and detachable links.
Starting with the 1st shot, every shot has a color of the detachable link and links surrounding it painted white.
1st shot detach link is RED, 2nd shot detach link is WHITE, 3rd shot detach link is BLUE, repeat.
1st shot has 1 link on both sides of the detach link painted white.
2nd shot has 2 links…painted white.
3rd shot has 3 links painted white.
2nd-to-last shot has all 90 feet painted YELLOW.
Last shot has all 90 feet painted RED.
If you are crabbing in a narrow channel to maintain course but happen to be headed towards a breakwater gate or bridge for which your crabbing width is too wide, what are 2 options you can do to reduce crabbing angle?
- Go faster. (not recommended)
- Have your bow get closer to the upcurrent side of the opening. When your bow passes next to it, use your rudder to swing your stern towards it. As your stern clears the opening, use your rudder to return to the center of the track / crab.
What is the danger of traveling up a narrow channel with a strong head current? What should you do if that dangerous thing happens?
If your bow gets cocked to one side, it might be too difficult to twist your bow back to the head bearing.
Back down until the ship is stopped relative to the water and let the current carry you downstream until the situation can be resolved.
OR
Back until way over the ground is lost, drop an anchor at short stay with engines stopped. This causes the bow to pivot nicely up current. Retrieve the anchor and continue your journey.
What principle is the cause of the Bank Effect for suction and cushion?
Bernoulli / Venturi
What are the 4 steps to Voyage Planning?
- Appraisal
- Planning
- Conferring
- Execution/monitoring
When does the Conferring stage get executed?
Navigation Brief
List 10 items you should discuss with your pilot upon pickup.
Maneuvering characteristics of your ship and lowest depth projection
Allowable deviation from track
Unpublished hazards to navigation
BtB radio comms
Ship-specific piloting and conning procedures
Use of tugs
Material casualties that may affect maneuverability of the ship
Material condition of the ship (oil leaks, steering system, etc)
Safe speed for all transit legs
Status of ECDIS-N
What is “Sweeping a Lee?”
Right before a pilot brings their boat alongside, you turn your stern upwind to create calmer waters for the pilot’s vessel
Where would you find a Kort Nozzle?
On a tug with directed thrust. It encloses the tug’s propeller, which enhances its efficiency, increasing the tug’s thrust ahead. It also steers the ship
What are 3 variants of propeller-steered tugs?
Voith-Schneider
Schottle
Harbormaster
Z-Drive
A tug loses all of its lines somehow. They ask to use yours. Should you provide them with a Nylon line?
No! They’re strong but stretches too much to provide a solid makeup for the tug. If it parts under strain, Nylon lines are lethal af!
What is the scheme for P&D Line distances?
GRYBWG, where G starts at 0 feet, R is at 20 feet, etc.
G0 R20 Y40 B60 W80 G100
What distance of lateral separation should a DDG be from an UNREP oiler?
140-160ft
At night, what lighting scheme should you attached to the P&D line?
2 blue lights at each marker: 60, 100, 140, 180 ft
Red lights elsewhere
What are the wake thumbrules for UNREPs?
5 feet of blue water between vessel wakes = 90 feet of lateral separation
40 feet of blue water between vessel wakes = 125 feet of lateral separation
NWP 14 requires that the distance between ships be no closer than _____ ft before tensioning.
140 ft
What are the 3 general steps to towing a disabled vessel?
Passing a Line
Rigging the Tow
Towing
Describe Ballot’s Law.
For the northern hemisphere, if you face directly into the wind, then the center of the storm is about 115 degrees to your STBD.
A constant wind direction with increasing velocity means you are in the direct path of the storm.
Wind that veers (shifts clockwise) around your vessel means what?
You are in the Dangerous Semicircle.
Wind that backs (shifts counterclockwise) around your vessel means what?
You are in the Safe semi-circle
What should you do if you find your vessel ahead of an approaching storm in the safe semicircle?
Place the wind on the STBD QTR and proceed at fastest spidd that you ride well.
What should you do if you are in the dangerous semicircle?
Choose a course as near as possible to a right angle to the storm’s path to maximize the distance to the eye’s closet point of approach.
