How much stronger is improved plow steel than regular plow steel?
Formula: SWL wire
= square of circumference / 2.5
Ventilate OR Do NOT Ventilate: Non-hygroscopic cargo: Cargo loaded in cold climate - ship steams into warmer climate
Do NOT ventilate
Defn: The difference between the dry bulb and wet bulb temperatures
Defn: The temperature at which condensation will occur for a given volume of air
What is the minimum safety factor that should be used when determining breaking strain?
List (3) main ways to reduce sweat damage to cargo:
1. dunnage (sweat battens) 2. tarps to cover top tier of cargo 3. VENTILATION
Name (3) advantages of a modern crane over the married fall system?
1. greater spotting area 2. safety 3. simplicity of ops
What is the ditty for ventilation of non-hygroscopic cargo?
"Hot to Cold - Ventilate Bold, Cold to Hot, Ventilate Not."
Defn: the weight of water vapor present in a given per unit weight of dry air
Defn: Occurs when the maximum amount of water vapor a volume of air can hold at a given temperature is present
When the dew point, saturation point, and wet-bulb temperature are all the same the air is said to be __________.
Formula: Breaking strain of wire
= 2.5 x square of circumference
Moisture that forms on the ship's structure and can drip onto the cargo as a result of temperature differences between the metal of the ship and the outside environment.
What powers the modern ship-board crane?
electro-hydraulics OR hydraulics
What can happen when oxygen and moisture are combined within a cargo hold?
What is one of the first initial actions you must take in the event of a fire onboard ship?
secure ventilation immediately
Ventilation can more accurately be described as _____ __________ for cargo holds.
Preventing moisture and damage to cargo that results from condensation within a cargo hold is the primary objective of what?
TRUE/FALSE: It is always beneficial to ventilate a cargo hold.
What can be fitted to the sides of a ship's cargo hold that serves to prevent cargo from contacting ship sweat?
Ventilate OR Do NOT Ventilate: When the dewpoint of the outisde air is lower than the dewpoint of the hold?
A ______ _________ on a crane indicates the angle of the jib.
____________ is a type of airborne damage to cargo that is caused by dust particles; ventilation does not help remove these particles.
Formula: Absolute Humidity
= specific humidity / volume
Ventilate OR Do NOT Ventilate: Non-hygroscopic cargo: Ship loaded in warmer climate - ship steams into cool climate and cools down
Moisture that may form on the cargo itself from the cargo.
The warmer the air the (more/less) air it can hold?
When the vapor pressure within a hygroscopic cargo exceeds the vapor pressure of a cargo hold the cargo will do what?
give off moisture
What is the ROT regarding dewpoints of a cargo hold?
Always try to have the lowest dewpoint in cargo hold
_________ is a type of airborne damage that is caused by vapors introduced to a cargo hold from odorous cargoes; ventilation does not help prevent this kind of damage.
Defn: the pressure exerted by water vapor present in a volume of air (expressed in in. Hg)
The term used for heaving on the winches of both booms of a married fall system in order to get the load up high enough to clear the bulwarks; Results in a great angle between the two falls and the two winches pulling against one another, placing great strain on all the gear involved
What occurs if additional water vapor is present with air in a saturated condition?
A ______ ____ on a pedestal crane prevents the jib from being raised too high.
Formula: Stress on Topping Lift
= (Length of topping lift) / (ht of mast x wt lifted)
Defn: The ratio of the amount of water vapor in the air to the amount of water vapor the air is capable of holding at that temperature.
Ventilate OR Do NOT Ventilate: Hygroscopic cargo: vessel sailing from warm climate to a cold climate
Which source of water vapor in a cargo hold causes the most problems?
Defn: cargo capable of absorbing moisture
Most damage to cargo occurs from _____ sweat.
What is the tool used to determine the dew point of a cargo hold while underway?
Defn: the weight of water present per volume of dry air
21% of air is made up of what chemical component?
What kind of ventilation do modern ships possess?
Defn: The temperature of the air that is measured accounting for relative humdity
Vapor pressure within cargo (increases/decreases) as the temperature increases?
Defn: A term used to indicate the steps taken to prevent damage to cargoes from condensed moisture in cargo holds.
78% of air is made up of what chemical component?
Forumla: SWL rope
BS / SF
The amount of water vapor that a given sample of air can hold varies directly with the ___________ of the air.
An increase of 20 degs. Fahrenheit will roughly _________ the amount of water vapor a given amount of air can hold.
The second-most common cause of moisture damage to cargo is from _______ sweat.
Defn: The temperature of the air when measured by a regular thermometer (that does not account for relative humidity)
What are (2) ways that water vapor can be introduced to a cargo hold?
1. outside air brought in by ventilation 2. hygroscopic cargos