News Release

Yanmar's HB Engine Admitted to the National Museum of Nature and Science

September 11, 2012
Yanmar Co., Ltd.

In 1933 Yanmar succeeded in developing the HB: the world's first commercially viable small diesel engine. In recognition of this momentous achievement, the National Museum of Nature and Science in Tokyo has registered the HB as one of Japan's "Essential Historical Materials for Science and Technology"*.

Yanmar's founder, Magokichi Yamaoka, recognizing that Japan was a country with a paucity of resources, endeavored to build a durable fuel efficient engine, finally realizing success with the HB engine. Since that day, Yanmar engines in Japan and around the world have been hard at work in agriculture, fisheries and construction.

The HB is a small horizontal water-cooled diesel engine with an output of 5 to 6 Hp.
In the 1930s, diesel engines were still large and unwieldy. Yamaoka's breakthrough dramatically reduced the size and weight of diesel engines making it possible for a single person to move one. HB engines were easy to operate and found wide use in agriculture, powering rice hullers, irrigation pumps and other machinery. In 1981, Yanmar produced its 5 millionth horizontal water-cooled small diesel engine.

This model is stored for safe keeping at Yanmar Headquarters. When the Yanmar Museum is completed in March, 2013, the engine will be moved there to go on display to the general public.

1. HB Diesel Engine:

HB Diesel Engine
HB Diesel Engine

* Essential Historical Materials for Science and Technology are chosen from "scientific and technological developments that represent a major accomplishment and are a significant influence on future generations" or "items that have a prominent impact on people's lives, the economy, society or culture", and are recorded in the Essential Historical Materials for Science and Technology Registry by the Director of the National Museum of Nature and Science.

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2. Inquiries:

Public Relations Group,
General Affairs Dept., Yanmar Co., Ltd.