Early Days in the Forest Service Volume 3

THE BOSWORTH TRENCHER
By Harold T. Wicklund
(Missoula Equipment Development Center)
(Division of Fire Control)

A pioneer is sometimes described as one who goes before to set the way for others to follow. He is usually a man of strong convictions and vivid imagination and willing to oppose the customs and thinking of the general run of people. Many will oppose him, some will follow until they find that the going is not as smooth as they thought, then return to the old ways. A few will become as enthusiastic as he is and will follow to the end the way he has set.

Such a pioneer was Jim Bosworth. At a time when manpower was both plentiful and economical, and handwork supplemented by horse-drawn plows the accepted method of controlling fires; he set a way which was far beyond the horizons of his contemporaries.

On March 10, 1934, he wrote this letter to the Regional Forester:

Attached is a rough sketch of a wild theoretical idea of mine of a power trench building machine, that I have had in mind for the past three years, which I think might work out to be a very practical piece of machinery by considerable experimenting. (I find no trace of this sketch. — H.T.W.)

My theory of the idea is a small compact air-cooled motor of six or eight horsepower, connected to the drive wheel by a transmission and worm or chain-drive that would give a speed of 2-1/2 miles per hour (in high gear) and 1/2 to 3/4 miles per hour in low gear. On the opposite side of the motor would be another transmission forward, reverse and neutral gears, being geared so that the attached brush would run at a speed of from 1000 to 2000 revolutions per minute. The size, shape and speed of this brush is to be determined by experimentation. It is assumed that a flexible steel wire, about No. 9 or No. 12, would answer the purpose of teeth or bristles. A universal joint between the transmission and brush would allow movement of one end of the brush right or left, depending on the width of the trench desired. Attached to the brace on the rear end would be a third wheel arranged to help support the weight and steer it. A gas throttle arrangement could be placed on the handle to work on the same principle as a motorcycle throttle. On the other handle, I believe a clutch arrangement could be worked out so that the machine could be stopped or started at any time without stopping the engine or brush or allow more time to dig the trench deeper in certain places if needed.

The brush to be housed in to keep rocks and debris from hitting the operator and the frame made of some light but strong material. It should be made to come apart in pieces that one man could carry so it could be back-packed off trails to the fire.

In discussing this idea with men familiar with trench construction in this locality, one of the points brought up was that with the drive wheel arrangement, it would not get grip enough on the ground to pull the machine on steep side hills. This could be overcome by a cat tread arrangement. Another point was that the revolving brush would pull the machine around in a circle; however, with the speed of the brush at 1000 to 2000 revolutions-per-minute, I do not believe this would happen.

One of the main objections is in running it parallel with a steep sidehill the front end would have a tendency to slide down. This could probably be overcome by hooking a chain or rope into the side of the machine and having one or two men hold it up.

I have never seen anything like it and the whole idea is based on theory, but considering the slowness and cost of trench construction, I believe we are justified in experimenting in some kind of a machine along this line and this may lead to a start and I am forwarding the idea to you for whatever action you may desire to take.

As a means of eliminating some of the heavy costs in maintaining plow horses in serviceable condition, as well as lowering the transportation costs, this idea may be worthy of serious consideration.

Whether or not he agreed with their opinions, Jim drew strength from controversial discourse with his associates. By the forceful manner of presenting his convictions, he was able to lead many of them beyond their original horizons and into the land of his visions.

This was the beginning of the Bosworth development program which was to gain momentum for six years and then taper off into disuse.

In the early '30's, Mark Forrest was in Research and Development for Engineering. He and Jim made up a test machine by mounting a brush arrangement on the end of a Wolff saw blade for observation only. From this experience, Mark constructed a small machine using a 2-horsepower engine and wire brushes, then later, steel springs. In use, this had to be carried by two men.

In the meantime, Jim had changed his plans somewhat and sent some new designs to George Duncan. Mark Forrest had left the service and was replaced by Gordon Conrad.

Here is a part of a memo by George Duncan which is not dated but must have been in 1937:

Description

Bendix 2.6 horsepower, 2-cycle engine, brush attachment in front, two handles, and single wheel, wheel barrow style, weight 70 pounds.

Progress

Difficulty in finding suitable power unit and brushes. Machine tried August 16. A line 160 feet long, 10 inches wide through small brush, grass and pine duff and gravelly soil was dug in 6 minutes or about 25 chains-per-hour. The brushes broke up badly after 15 minutes running.

There is no doubt but that the Bosworth Trench will work out as an efficient firefighting tool.

Later this trencher was taken to the fire on which Lloyd Hornby had a fatal heart attack but it was not used.

Fire Control, the Washington Office, and Engineering and Operation of R- 1, were now all getting into the picture, realizing that the Bosworth Trencher had great possibilities. A thorough search was made of the market in an effort to obtain an engine of suitable horsepower and weight ratio. The nearest they could come to it was a Reed-Prentice engine used on the Wolff chain saw. There were three of these saws in the Region. Any brushes or springs they were able to get would not stand up with use, but about this time Conrad came up with an idea of using the hammer hill principle on the trencher.

Gordon Conrad, Ed Peterson and Earl Duvall, who now had the responsibility of development, mounted a Reed-Prentice engine in a wheelbarrow-type frame with a motorcycle wheel in front. Through two sets of bevel gears they drove a horizontal shaft on which they mounted two hubs with nine swinging hammers on each one. These were revolved at 800 revolutions per minute and were adjustable to throw material forward at 45 degrees either side from the line of travel.

This was the best machine yet, and, in fact, the first one to stand up under continuous use. It created a lot of enthusiasm toward further development.

February 8, 1938, George Duncan left Missoula with this machine, going first to R-3 where he demonstrated the trencher on two forests, then to R-8 where he made 10 more demonstrational tests. Duncan's report and those from various forests where he had demonstrated were very good. In the South, they mention several times of trenching more than one chain per minute. This must have been in sandy soil with no large roots. A few broken hammers were the only trouble experienced.

In the search for an engine, they found that no more Reed-Prentice engines could be had at a reasonable price but at this time the Bendix people came out with a 2-cylinder. 5-horsepower, 2-cycle engine with a vertical crankshaft weighing 41 pounds. One of these was purchased and a lightweight trencher made up using it with the same arrangement of swinging hammers as on the Reed-Prentice machine.

This is where I entered into the Bosworth Trencher development program. It came about this way. I was called into the shops from my work in the field with the Lolo Forest and put in charge of the machine shop. About this time Earl Duvall, who had been doing the actual construction of the trenchers, transferred out of the Service. Bill Grose then took over the machine shop and I devoted most of my time to development, testing, demonstrating and training for the next several years.

The first machine I built turned out to be a dismal failure. Someone promoted the idea of using a heavy 12-horsepower motorcycle engine. Conrad did the best he could in designing, and I did the best I could in constructing this trencher, but it was so heavy and awkward that even Paul Bunyan couldn't have handled it. With all its power, the trenching unit did no better work than the old one had done.

The next development was redesigning the Reed-Prentice model, making it a lot lighter and easier to handle and demountable for packing.

The first time we used this machine was to help the Missoula District build a fire guardline on Mount Sentinel. Then it was given a number of hours testing and was demonstrated at a regional fire school.

On August 16, I went with Clarence Sutliff, Fire Control, R-1; Roy Headley, Fire Chief, Washington Office; and John Kinney, Operation, R-4, on a trip to demonstrate this trencher on two Forests of R-1 and three in R-4. Mr. Headley had shown interest in the trencher through his letters, but was also somewhat skeptical. In a letter of July 27, 1937, he said:

It would be easy to let our interest in the engine driven tools lead us to step over horse-and-plow dollars in our search for mechanical engineering dimes. The horse-and-plow needs development, to be sure, but the need is for management and human engineering development rather than mechanical engineering.

Now for the first time he was seeing one in operation.

On the Coolwater Ridge in the Nezperce Forest where we had kept up with a 25-man clearing crew trenching in heavy brush and roots, then worked with no clearing except the removal of logs, he was astonished and said, "I have always been in favor of the horse-and-plow unit above anything else but now I will admit that this trencher will do more than any horse-and-plow unit."

On the way to the station, he accepted the trencher as a part of the Fire Control family and officially agreed to the name Bosworth Trencher in recognition of Jim's contribution of the original idea.

The Sunday before Labor Day I took the trencher to a fire on the Kaniksu Forest. The next day we were on the fireline 12 hours doing all the trenching behind two 25-men C.C.C. clearing crews. We could trench a lot faster than they could clear. I estimated that we worked between three and four hours out of the twelve; the rest of the time we spent waiting on the clearing crews.

There had been steady if slow progress, and now we had a machine which it seemed would be acceptable after a few changes were made. Samples were made and tested and it was agreed that no further changes were indicated. We then constructed three trenchers with Reed-Prentice engines and five with Bendix engines. Six of these machines, two Reed-Prentice and four Bendix models, were shipped to R-8 in the early part of December.

A letter from Roy Headley December 22, 1938, gave a firm order for 30 to 34 trenchers to be paid for with money from the Washington Office, hoping they would cost no more than $350 each. They were to be distributed four each to Regions 1, 4, 5, 6, 7, 8, and 9, and three each to Regions 2 and 3.

By December 29 all instructions had been given to construct 40 Bendix model Bosworth Trenchers to be completed and ready for delivery by March 31. Early in January our drawings and specifications were completed, parts were being ordered and construction begun. I was given the responsibility of constructing these machines, with the facilities of the shop to be used as needed. I used the interchangeable-parts, assembly line method of manufacturing. Jigs, fixtures, and mandrels were made for shaping, forming, machining and assembling all parts or sections. After all parts were made and sections welded, the machines were assembled.

We completed the assembly and testing of these trenchers about the first of May. The original allotment estimated the cost at $350 but we had made them for $265. With the balance on hand, parts were purchased and 15 more machines were built.

Trenchers were shipped to eight Regions and to eight Forests in R-1. I spent a month demonstrating and training on these Forests where I contacted most of the overhead from the Ranger Districts and Forests. The two trenchers used in this demonstration were operated about 30 hours each. Some mechanical and structural failures were encountered but most of them were corrected later. I wrote a report about these mechanical problems which was published in Fire Control Notes of January 1940.

The machines did very good work and were well received by most personnel and highly praised by some. Good reports came to Fire Control about this demonstration and training trip.

I set up a fire unit of two trenchers, necessary accessories and a standby crew. We were on six fires that summer and did very good work on some of them but had some mechanical trouble on others.

During these 4 years, from the first model to the mass production of 60 machines, a small group of dedicated men carried most of the burden of research, designing, testing, demonstrating, improving and putting this machine into fire-suppression planning. They, too, were pioneers and willing to devote time and talent toward the development and promotion of the trencher solely for the benefit of the Service.

While most men are loyal to the Service, it seems that there are always a few whose only thought is selfishly of their own status. We had some of this type and while they had considerable ability and aided in the trencher development, their adverse influence prompted by selfishness and petty jealousies were mostly responsible for the final decline of this program.

Using a summary of the complaints reported by many users, we carried out an experimental modification project to correct the defects which caused the troubles. Most of the difficulties were with the engines which had been designed for propelling small boats where power requirements were constant. The most serious of these was the destruction of the bronze connecting rods at high engine speeds, usually caused by lifting the hammers out of the trench with engine at full throttle. We remedied this by designing a loose-needle roller bearing connecting rod with a removable cap. This was radically different from anything in use at that time and was considered by some engineers as not usable, but test proved its worthiness. Engines equipped with these rods could be operated for long periods of time at extremely high speeds without any damage. At present all better-grade, high-speed 2-cycle engines are using this type of connecting rod bearing.

A list of the necessary modifications was made and approved. A bid was let and a purchase order issued for 125 conneciing rods.

Here is a part of a letter sent to all Regions:

The Bendix motors on Bosworth Trenchers have been developing numerous failures due mostly to being unable to control the speed when not working, poor lubrication and poor bearings.

The Washington Office has allotted this Region funds to do the following jobs on the machines owned by all Regions:

1. Substitute pin (needle roller) bearing connecting rods for the factory installed bronze rods.

2. Drill crankshaft to permit free passage and equalization of fuel to both cylinders. This also facilitates lubrication.

3. Install new air cleaner.

4. Install speed control (governor).

Each of these changes considerably increases the effective power output and length of life of these motors.

Jim had been assigned to engineering equipment development for several months and was largely responsible for these improvements. But, here again, his pioneer visions had advanced beyond those of his associates. They followed him for a while, but when he was again transferred to a forest a few who had been opposing him and thought that his popularity might thwart their plans of advancement, went to work with adverse influence to convince those in charge that the connecting rods were not needed and that it would be a waste of money to buy them. The purchase order for these rods was cancelled and only the other modifications were made on the engines.

This engine-driven tool should now have been ready to step over Roy Headley's horse-and-plow units with dollars of its own instead of dimes. Creative engineering had brought it a long way but the management and human engineering necessary to consolidate the gains were not given to it. The engines had been improved. With proper management and good training, they produced some good results. The only complaints were about minor troubles which could and should have been corrected locally, and many were of the same old trouble - overheating and connecting-rod failures.

The machines were used very little in 1941 and then came the war! Some of us were far from the timbered forests and those who were left at home, for one reason or another, did not use the Bosworths.

Many changes had been made in the personnel of the Forests when I returned to Fire Control in 1945. There was also a change in the attitude toward the trenching units. There was no evidence of the type of enthusiasm that had prevailed during the period of development. Training demonstrations were given but we didn't get any of them out on fires. Within two years most of the Bosworths were declared surplus and sold.

I could easily write a volume about Jim, his trenching machine and his inventive activity in general. I knew him for years, have discussed his qualities with many of his friends and was closely associated with him for several months while he was doing research development work for Engineering. Using a fund of logical thinking, together with his creative imagination, he presented many constructive ideas which were innovations, but practical. They were not always accepted and sometimes were met with opposition, but they were not lost for they set a way for someone else to follow.

A short review of the life span of the trencher shows that Jim had spent three years perfecting the idea before formally presenting it to the Service. In three more years it was accepted. During one additional year it was received with an enthusiasm which flared up and expanded for two years, then died out. Within two more years, or eleven years from its inception, it was rejected. The economy of such a machine was the motive of its origin. The good showing of the earlier machines interested many administrators enough to encourage its development. A few dedicated people boosted it to a place where it was recognized as an outstanding invention capable of economy and production beyond any earlier anticipation. Engineers were available with ability to overcome any mechanical failures. The origin was human, the success mechanical, and the failure human.

Jim, the pioneer, had rolled back the horizons and set a new way which many followed as long as the way was easy to travel and they could feel themselves included in the glory of success. But they failed to help the dedicated few when troubles were encountered. Good management of a strong organization with continuous development, training and application to its use could have kept this machine going.

Looking back over these 29 years, we can see that Jim's visionary thinking was many years beyond that of the average forest officer. The course he opened for us is still visible. Several half-hearted attempts have been made to follow it, but lack of interest of those who should be the most interested turns the travelers back. It is not as rough as it looks. Some day, probably soon, we will be permitted to travel it again, and somewhere along the way we will pause long enough to erect a memorial to Jim Bosworth.