JIM OLSEN
MARINE SURVEYOR-- ENGINES AND MACHINERY A SPECIALITY--
JIM OLSEN
MARINE SURVEYOR-- ENGINES AND MACHINERY A SPECIALITY--
Society of Accredited Marine Surveyors
Accredited Marine Surveyor #449
With Additional - E - Engine Surveyor Rating
101 Atlantic Avenue - West Sayville, NY 11796-1901
Office: (631) 563-0077 Skype: jamesolsensurveyors
Marine Survey - Consultation - Appraisals
During the phase of the survey called "Sea Trials", and only after the Surveyor has pre-determined that the engines are fully warmed up, operating on all cylinders without excessive noise or smoke, and idling smoothly with good oil pressure and normal temperatures, will the Surveyor call on the operator of the vessel to begin the process of running the engines in gear and thru out the full RPM range the engines are rated for.
The main sea trial ranges are:
Normal cruise, which is usually and most commonly, that RPM that is sustainable for 100 percent continuous service. Normally this is also the most fuel efficient RPM, and the one most selected for sustained operation when underway. On the older gas, carbureted, V8 engines this was the RPM just before 4 barrel operation, with the vessel - on plane - and found usually in the range around 2800 to 3000 RPM. With fuel injected gas engines, as with most diesel engines, continuous service ratings are usually closer to top RPM. Many factors will influence the optimum cruise RPM selection range in these engines. Manufacturers specifications, and loading / weather conditions will vary widely.
Maximum Cruise on older gas V8 engines 3600 RPM is the most common upper cruise RPM range, and is usually reserved for limited and intermittent service cycles. It is at this RPM phase that the surveyor will make all final checks and readings preparatory to determining the all important top RPM readings and conditions. Again, as with newer gas fuel injected (higher RPM) engines, and with most low and high speed diesel engines "It all depends" will determine the RPM choices for this phase of the diagnostics. -Turbo operations will also be a focus at this time.
W.O.T. Wide open throttle is the final and very important phase of the sea trial and is usually subject to the widest range of "Judgment Calls" regarding factors such as:
The age of the fuel and fuel filters
The amount of fuel and other inventory aboard
Bottom conditions such as last bottom cleaning
Tide sea and wind conditions
And so on, and so on...
But you get the idea I am sure. That said, there are minimum standards that must be met, almost regardless of other (normal) factors, and by normal, it is meant that for all practical purposes. Sea trials in the average boat cannot be conducted in gale winds, high seas , or in confined areas, and, or consisting of a series of short intermittent bursts of speed.
This surveyor will always strive to provide you with the best that the boat can do, up to and including its design limitations and potential . but it must always be remembered that finding a boats breaking point will not be the mission of the sea trial, especially if you are looking at older boats and higher hour engines.
At some point in your negotiations, the seller / broker must acknowledge that the vessel will be asked to attain its wide open throttle operation for a reasonable period of time , but certainly not to exceed any sign of distress. This can sometimes be a real stumbling block, best settled up front, and not found out on the morning of the sea trial that the owner "Has never opened the engines up, and never will" - unquote--
A full bore, full vessel survey will take the best part of a long day. And a professionally surveyed boat will also take many hours at the computer after the survey -- to complete the report -- With proper planning and cooperation between all parties, most reports are completed and delivered in about 3 to 4 days from the date of the survey.
"I ALWAYS GO THE EXTRA MILE"
© J.H. OLSEN CORP.
