ARPA Assisted Casualties

[curious_cadet]

Hello All!
In the midst of researching casualties where ARPA was the main factor to the incident whether it due to primary navigation or faulty equipment. Any and all ideas would be greatly welcome!

Cheers

[BMCSRetired]

Hello All!
In the midst of researching casualties where ARPA was the main factor to the incident whether it due to primary navigation or faulty equipment.

ARPA is like anything else, a tool. I can not think of a single instance where ARPA would be the primary cause of an incident. Nobody should ever rely entirely on any single piece of equipment including ARPA while on watch. If it was the main factor in an incident, then the operator is at fault not the equipment because he/she is responsible for ensuring it is working correctly by comparing the data to other sources (visual bearings, AIS, etc...) and responsible for the watch, not the ARPA.

My two cents...

[jdcavo]

Collision of the SS Exxon Chester and M/V Regal Sword: http://www.ntsb.gov/recs/letters/1980/M80_53_54.pdf

[cappy208]

As Rod Serling used to say..... "You are now entering the twilight zone"

This is actually a misnomer. ARPA does not cause the accident. The mariners use of ARPA is what causes accidents. Both the mariners USE of AND the LACK of use of ARPA contributes to accidents. The knowledge of when, and how to use ARPA is what the class is for. However understanding the limitations and conditions which ARPA is useful is probably more germane to the subject than the actual use of ARPA. I don't feel the limitations of ARPA and its use are stressed often enough, and in fact after the original ARPA course one NEVER hears these discussions again.

One of the best explanations on the subject I ever received was: The Pilot aboard the Sea Pride 2 making a turn down the Delaware R ran into the Bulkhead Bar power lines. When asked if he was using ARPA to plot the 'mystery target' His response was... 'ARPA was not being used since we were making constant course/speed changes.' This was the end of discussion, and no further references were made concerning ARPA and it's use. But If you were to respond with anything else (showing you didn't realize that ARPA was un usable under the circumstances) then you would be negligent for not knowing how to successfully use ARPA. Kind of like a double edge sword, it cuts both ways, no matter how you hold it!