by Rick Forrester

Keeping the trail free of fallen trees or overhanging branches routinely requires the use of chainsaws and powered extendable pole saws.  With weekly use, the saws routinely need servicing, especially carburetor cleaning and adjustment. Adjustments change based on the condition of the saw, grade of gas used, oil/gas ratio, elevation of where the saw is being used, and even the time of year when the gas is purchased.  One of our tools of the trade is a carburetor service kit that contains the specially shaped wrenches, reamers, and brushes used by various saw manufacturers such as Stihl, Echo, Ryobi, Poulan, etc.  It also has a tachometer to measure engine RPM (revolutions per minute). 

There are typically three screws on a two-cycle engine that need adjustment: L for low speed, H for high speed, and I or LA for the idler jet. The different manufacturers have different letters for the three screws but the carbs generally perform the same way.  Although many people can hear the various sounds of a properly running saw when idling, cutting, or running at high speed, the use of a tachometer gives you an extremely helpful visual display of the rpms.  It is especially if you have bad hearing!  For an RPM example, many Stihl saws run at a high-speed rpm of around 10-14,000 and low idle around 3000 each depending on the model.  The various manufacturers often don’t put the target RPM values in Owner’s Manual in order to force you to use their service departments, but they can be found in the “Service” manuals which you can buy separately from either the manufacturers’ website, authorized dealer service centers, or from independent service manual providers.  However, a little internet searching can dig up the proper values for your saw. The kit the Fosters work crew uses has all the necessary tools and can be purchased from Amazon for about $30. 

Keep those saws running great down on the trail!

by Erick Wikum

My typical column provides tips to address a specific safety concern you may encounter when using the Little Miami Scenic Trail. In this month’s column, I would like to provide you with a tool you can use to determine which of the many, many potential safety issues deserve your attention.

Failure Modes and Effects Analysis (FMEA) provides a step-by-step method for identifying, analyzing, and preventing or mitigating potential failure modes. FMEA includes the following steps:

• List potential failure modes.
• Analyze each failure mode as to its effect or consequences based on both its likelihood of occurring and its impact.
• Develop plans to prevent or mitigate the failure modes having greatest effect.

To understand FMEA better, consider the following list of potential failure modes and corresponding effects.

Now, let us consider how to prevent or mitigate the first four failure modes, which have highest effect in the worst case. We can prevent collisions caused by ourselves by slowing around others, announcing our presence (“on your left”), and giving others a wide berth, and avoiding unexpected movements (like suddenly turning around on the trail). We can mitigate the effect of collisions caused by others primarily by being alert. To mitigate the potentially life-threatening effects of heat exhaustion and heat stroke, we can avoid the trail during the hottest hours of the day, hydrate, and dress appropriately. We can prevent or mitigate the effects of a slip, trip, or fall by exercising care when the trail is uneven, wet or icy, algae- or leaf-covered, wearing proper footwear, and wearing a helmet. To mitigate the effects of a crosswalk accident, we can come to a complete stop, check carefully, and proceed across a street only when it is completely safe to do so.

The effects of failure modes vary from person to person based on activities pursued, physical condition, etc.  I encourage you to construct your own list of failure modes and to conduct your own analysis to determine which failure modes deserve your attention.

Fortunately, just a few actions can mitigate the effect of many potential failures and those actions include (a) paying attention to what’s happening around you, (b) exercising caution around other trail users, and (c) wearing a helmet when engaged in wheeled activities.

Identify, analyze, and mitigate.  Add FMEA to your toolbelt and you will be equipped to use the trail safely.

October 2022

by Rick Forrester

Take time out while walking or biking on the trail and look for a jewel of a plant in the forest!  The biological name is “Impatiens Capensis” but a few of its common names are orange jewelweed, common jewelweed, spotted touch-me-not, or orange balsam.  Believe it or not, it is actually related to the ornamental Impatiens we are fond of using in our landscaping at home.  

The flowers range from yellow to orange with red splotches on three lobes.  The leaves are alternate, smooth, have teeth on the edges and are silvery underneath.  Jewelweed is usually 3-5 feet tall and they are blooming right now (August/September) down on the trail!  Hummingbirds are the major pollinator with bumblebees being the next best.

The plant has some incredible, unique characteristics.  The seed pods, once fully mature, are angled down from the stem, and the riper they are, the farther back they’re cocked, resulting in a spring-loaded mechanism which will shoot the seeds several feet in a process called ballistochory or explosive dehiscence.  (Explosive dehiscence – what a delightful phrase!)   if you gently pull the bottom of the pod toward you with one finger, the pod instantaneously splits into four curled sections and the seeds go flying in all directions.  Hence the name “touch-me-not”.   It is great fun to do this with your children!  But if you don’t have your kids along as an excuse, go ahead and do it on your own when no one is looking!

If you pick up the individual seeds and peel back the outer cover, you will find a beautiful turquoise-colored seed.  Hence, the derivation of the name “jewelweed.”  The often-silvery underside of the leaves adds to the name jewelweed.

Not stopping at that, the stems of the plant contain triterpene glycosides or “saponins” which act as a foaming agent.   What that means for you as a hiker is that if you brush up against stinging nettles or poison ivy, you can crush the stem of the jewelweed plant and use the juice to neutralize the sting of the nettles and also to reduce the inflammation from exposure to poison ivy.  The crushed stem juice is also a fungicide and can be used to treat athletes’ foot.  You can buy jewelweed extract at homeopathic stores, though it does not have the effectiveness of the oil freshly mashed from the plant unfortunately.  Do exhibit caution, though – for some reason, jewelweed often grows side by side with nettles and poison ivy!

So, have some autumn fun down on the trail firing seeds and spreading goodness around the forest floor with friends and family!  You’ll be helping plant the crop for next year’s jeweled adventures while you’re at it.

Below: Jewelweed pod ready to explode!

Below: Exploded pod and covered seeds

Below: Seed cover removed, revealing the jewels!

September 2022