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 Author  Topic: Packard Manual - Development of Packard Marine Engine - Missing P


Post a Reply To This Topic    Reply With Quotes     Edit Message     View Profile of Dick   Send Email To Dick Posted on: May 25, 2024 - 3:32pm

IPackard Manual - Development of Packard Marine Engine - Missing Post Recreated

April 22 2024
Posted By: Jerry Gilmartin
Topic: Packard Manual - Development of Packard Marine Engine

Hey Good News!
I came across a booklet called Development of Packard marine Engine during WW2(September 1938 to April 1945) by Marsden Ware Head of Marine Engine Development. In this booklet he explains what this gear is for. Its official name is the Packard Bevel Pinion 2:1 Reduction Gear BP-1. It was designed in response to a request from the US Army to place inside their 104' Air Sea Rescue Boats.

Here is the transcript of the explanation given in the book on pages 12 and 13

2:1 Reduction Gear for the 4M-2500 engine (Reduction Gear Model BP-1)

The Army, in adapting the 4M-2500 engine to the 104’ Air-Sea Boat, desired to have a 2:1 reduction gear. The design of the boat was such that a reduction gear should provide a more efficient result. Being unable to obtain a suitable reduction gear of sufficient capacity from other sources, they requested us to design and build a suitable unit and this resulted in Packard gear BP-1. This uses bevel planetary type gears with four pinions mounted on the output shaft. Gleason Zerol type of gearing was specified.

Layouts on this were started in October of 1942, and detailing started November 6. The first production unit was shipped April 3, 1943. A total of 440 have been built to date. A photograph of this unit is shown in Appendix H.

While this gear was designed specifically for the 104’ boat, it is interesting to note that it had other uses. Some of the early gears were shipped abroad for purposes which have never been disclosed to us. Approximately thirty have been used in so-called “sea mules” which are used as tugs and for moving barges, etc., in harbor work. The original sea mules were engineered largely by Chrysler. Some of the later larger units have been equipped with Hercules diesel engines and the Packard gear. With a 6:1 reduction in the Hercules engine, the overall reduction with the Packard gear becomes 12:1. These units were tested late in the fall of 1944, and showed satisfactory results on tests, but we do not have much information on actual service experience.

Here is a photo from the book.



April 30 2024
Posted By: Dick
Reply: Packard Manual - Development of Packard Marine Engine

The following is a .PDF Jerry asked to create from iPhone photo, click on the link below:

Dick . . . .


April 30 2024
Reply: Packard Manual - Development of Packard Marine Engine

Excellent! Thanks Jerry and Dick for your dedication to our passion.
Take care,


May 6 2024
Posted By: smallwi
Reply: Packard Manual - Development of Packard Marine Engine


Thank you for this post! You are appealing to my mechanical engineer sole! I am trying to get to Portland again this summer to hear these engines hum again.


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