Relationship Between Charter Party & Tactical Performance
There is no relationship between Charter Party Performance and Tactical Performance. In many instances it is possible to have a passage where the vessel meets the warranty requirements of the Charter Party with less than satisfactory Tactical Performance. It is also possible for a voyage to reflect good Tactical Performance and bad C/P performance. For example consider the voyage video below.
Quantifying Tactical Performance
To assess Tactical Performance the balance between safety of vessel
and prosecuting the voyage with utmost dispatch must be expressed logically to facilitate
computer modeling. Consider first the
ideal passage from point A to Point B where the sea surface is flat calm and
there are no surface currents. The Optimum Track is the Least Distance Track
(LDT)
which is the shortest distance between points A and B.
Any deviation from the LDT
would be an unjustified waste of bunkers and daily hire.
Accordingly, the fuel and time
“budget” for such a voyage is that which would be
consumed on the
LDT.
Now consider the same passage with “bad weather” on the LDT as
indicated by the red ellipse. The master and/or weather routers may decide
that the most prudent track is well south as indicated by the green line.
This
may be because the master’s definition of what constitutes bad weather
extends well beyond the red ellipse.
For the purposes of Tactical Performance the budget now becomes the amount
of time and fuel required to steam on
the Adjusted Least Distance Track (ALDT).
The Adjusted Least Distance Track (ALDT) becomes “Par for the Course”. If, after post voyage simulation, the Actual Vessel Track (AVT) is shown to require less time and fuel, then Tactical Performance is positive. If more time and fuel is required on the AVT then Tactical Performance is negative. For tactical performance to be evaluated uniformly across a fleet, “bad weather” must be clearly defined.