After numerous trailer problems, both mine and those on the job, I've figured out what seem to be the best compromise for skiff trailers and trailers for boat a bit heavier, but similar in size than the C-Dory 25.
At work, we tow almost daily, so a day with a trailer out of service is a day that we have a survey team sitting around, waiting on their trailer, so that they can survey for various critical navigation missions. The cost of these trailers may seem expensive initially, but compare that to a trailer that sits in the shop for repair each month for a dozen times over just a two year period. This in addition to a crew that we tax payers are paying to sit around for a few days waiting on their boat trailer about once every month.
After many lessons leaned, the number one lesson that I have drilled in my head it to buy a trailer that has minimal moving parts and is the most durable with the least service requirements.
The attached files are my best shot at meeting these goals ( I had several trailers delivered over the past few years meeting my requirements), and though my troops wanted multi-roller trailers for all the bad ramp that we use, they are now all quite happy that the trailers are reliable and they can easily launch and recover at even the poorest ramps.
Work Item 1
STATEMENT OF OBJECTIVES
for
VESSEL CAWOOD BOAT TRAILER
1. SCOPE
1.1 Scope. This work items describes the requirements to manufacture and provide a boat trailer for the US Army Corps Survey Vessel CAWOOD.
2. APPLICABLE DOCUMENTS
US Army Corps of Engineers Vessel CAWOOD Information Sheet
3. REQUIREMENTS
3.1 Construct and provide boat trailer.
3.1.1 Boat trailer shall be designed to fit a 25 foot survey boat built by Munson Manufacturing, Incorporated (see applicable documents). Trailer shall be rated for approximately 10,000 lbs load capability. The gross vehicle weight (GVWR) shall be equal to the load capability, plus the weight of the trailer. Trailer overall width shall not exceed the state of Virginia’s legal trailer width, that does not require an oversize permit.
3.1.2 The trailer’s major structural members shall be aluminum. All aluminum material used for construction of the trailer shall be marine grade. All steel material used shall be hot dipped galvanized. All fasteners shall be of non-corrosive materials.
3.1.3 Trailer hitch assembly shall be 2 5/16” ball type hitch that exceeds the GVWR. A lockable device be provided to lock the trailer tongue latch and shall have a resettable combination, such as ABUS 1801B/50 B or equal.
3.1.4 Support system for boat hull shall be self centering bunk system. Bunk top surfaces shall be made of ultra-high molecular weight (UHMW) polyethylene.
3.1.5 A winch stand shall be fabricated and installed for specific boat’s boat height and clearance. An electric winch shall be installed with a minimum rating of 12,000 lbs., similar to a Warn M12000. Winch cable shall be of non-corrosive materials. The winch stand shall have a bow stop. A tie down/ratchet strap shall be provided and installed to hold the bow and the rear of the vessel onto the trailer.
Note: Large capacity winch is a requirement in case vessel cannot be power-loaded if boat’s propulsion system does not function or if ramp used is too shallow for engine’s outdrive to be lowered and utilized as a means of power-loading.
3.1.6 Trailer jack stand requirement. A heavy duty electric trailer jack stand shall be mounted near the front of the trailer. Jack shall have a flat (non-rolling) base.
3.1.7 A heavy duty battery shall be mounted near the front of the trailer that provides power to the winch and electric tongue jack and is wired to be charged by the tow vehicle. The battery shall an AGM type battery and shall be in a box with a lockable device to prevent theft. The lockable device shall have a resettable combination lock provided, such as ABUS 1801B/50 B or equal.
3.1.8 Fabricate and install fenders capable of being walked on to allow entry and exit of boat while trailer borne.
3.1.9 Trailer shall have two axles. Trailer axles shall be torsion controlled (no leaf springs). Wheel bearing lubrication shall be either constant pressure style grease system with serviceable zerk fitting and shall have hub protectors installed, or oil bath hub system.
Note: Wheel bearing grease system shall be compatible with brake system manufacturer’s requirements.
Note: As per the requirements of paragraph 3.1.2 the axle and the torsion arms shall be galvanized. The axle shall be galvanized on the interior as well as the exterior.
3.1.10 Brakes shall be electric over hydraulic for each wheel and shall be heavy duty stainless steel disc, DeeMax 316 SS or equal. Brake lines and associated fittings shall be stainless steel or other non corrosive materials DOT and SAE approved.
3.1.11 Tires shall be radial trailer design. Tire and wheel assemblies shall be rated to exceed the GVWR. All tires shall be high speed balanced. The trailer shall have a plaque installed on each side, near the tires, that states the recommended tire inflation pressure.
3.1.12 A spare tire assembly and tire mount shall be installed near the front of the trailer. The spare tire shall be mounted with a complete hub assembly. Spare tire shall be high speed balanced. The spare tire shall have a lockable device to prevent theft. The lockable device shall have a resettable combination lock provided, such as ABUS 1801B/50 B or equal. Spare tire shall have a heavy duty, UV resistant cover installed to prevent UV damage.
3.1.13 Lighting and wiring requirement. Wiring system shall be groundless type with no bare connections exposed (water-tight sealed connections). A 7-blade RV type electrical plug shall be mounted at the front of the trailer, with a pigtail to reach tow vehicle. Lighting shall be DOT approved light emitting diode (LED) sealed/waterproof type. Install a license plate bracket to the left rear of the trailer.
3.1.14 Load guide requirement. Load guides shall be installed near the rear of trailer and shall extend above boat. Load guides shall be lighted at top of guides with LED Pipe-Light 1-PL 1019 or equal. Load guide lights are in additional to all other DOT required lights on the trailer.
3.1.15 Provide and install a tool box. A small aluminum tool box shall be mounted near the front of the trailer. The tool box shall contain all necessary tools required to change a tire. The tool box shall contain two wheel chocks. The tool box shall have a lockable device to prevent theft. The lockable device shall have a resettable combination lock provided, such as ABUS 1801B/50 B or equal.
3.1.16 A ladder shall be fabricated and installed on the front of the trailer, to allow embarking and disembarking of the boat while on the trailer. Ladder treads shall have surfaces that are skid resistant.
3.1.17 Trailer shall be striped with DOT approved reflective type tape around its entire perimeter to aid in visibility.
3.1.18 Provide and install a walkway on the trailer. Fabricate and install a walkway inside frame of trailer, from front to rear of the trailer, aft of the winch support. Walkway shall have a surface that is skid resistant.
3.1.19 Install a label plaque to the trailer with information to include model number, VIN, GVWR, GAWR, tire information and manufacturers nomenclature. Additionally, the VIN shall be permanently stamped into the frame of the trailer in the general location of the manufacturers label plate.
3.1.20 Fit the trailer to the boat. Fit-up shall include adjusting the trailer until all supports of the trailer provide equal contract to the vessels hull and manufacturers recommended tongue weight.
3.2 Test the trailer with the boat loaded on trailer. The contractor shall test the trailer at a boat ramp in the Hampton Roads region in the presence of the COR. Testing shall be performed to demonstrate that the trailer is road worthy and that the boat is capable of being launched and retrieved with minimal effort.
3.3 Warranty requirement. A warranty shall be provided that provides a minimum of 2 years without exclusions. Without exclusions also include replacement of any materials that corrode.
5. QUALITY ASSURANCE
5.1 Inspect trailer for weld and mechanical defects prior to leaving manufacturing facility. Inspect the trailer for non-compliant materials. Correct all defects prior to trailer leaving facility.
6. NOTES
6.1 General information about the hull’s bottom.
Note: All measurements provided are approximate and it is the contractor’s responsibility to measure the hull’s under body interferences for fit up of the trailer.
6.1 .1 The boat’s single beam sonar transducer is located on the bottom of the hull, starboard side, 20” inboard of the chine and 9’ forward of the stern. The transducer and fairing measure approximately 2’ long and 9” wide.
6.1.2 The boat’s ball check transducer is located on the bottom of the hull, port side, approximately 2’ inboard of the chine and 9’ forward of the stern. The transducer and fairing measure approximately 1’ long and 7” wide.
6.1.3 The boat’s engine sea water intake is located on the bottom of the hull, starboard side, approximately 2’ inboard of the chine and 3’ 6” forward of the stern.
6.1.4 The boat’s generator sea water intake is located on the bottom of the hull, port side, approximately 2’ inboard of the chine and 2’ forward of the stern.
6.1.5 The boat is a monohull with a V configuration from bow to stern. On the bottom, the last few feet of the centerline of the bottom has a vertical plate attached for purpose of aiding tracking.
6.1.6 The existing boat trailer has height of boat bottom at the stern of approximately 22 inches from the ground. The new trailer shall not exceed this height and a height of less than this is strongly desired.
6.1.7 The boat’s bow eye to transom (excludes trim tabs and outdrive) is 21’7”.
6.1.8 Munson Manufacturing, Incorporated is not in business, so hull measurement information is the responsibility of the contractor, providing this trailer.
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