By far the biggest burns we participated in this past year were a pair carried out on the Massachusetts Military Reservation (MMR). Over two full days the prescribed burns on the MMR covered~330 acres. Both days we had highly active fire behavior, culminating with flame lengths somewhere around 100 feet high and a smoke column that (apparently) was visible from across the bay in Provincetown (35-40 miles). A few days ago I posted pictures from Day 1 of these burns, today is Day 2’s turn.
Again, during the second day our primary job was to hold one of the flanks of the burn. Unlike the first Rx at MMR however, this time we were tasked with keeping our flank burning in lockstep with the far side. Another team was on the true internal ignitions, but we still got plenty of torch time over the course of the day.
The second day’s total hovered somewhere around 230 acres, finishing in a spectacular 100+ foot display that was burning deep inside the unit. We had an easy time on our flank, in part because the vegetation was quite forgiving — A mix of tightly packed dog-hair pitch pines and fuel heavy (but otherwise clear) forest floor. The picture below is a good example of one of the “roughest” areas we were responsible for, the tightly packed pines in the lower portion of the picture acted like ladders, which allowed the flames to reach the upper reaches of their neighbors easily.
There wasn’t much we could realistically do to prevent those trees from torching, instead we mitigated the hazard (of having a tree torch on the perimeter) by having an engine on scene and ready to dowse spots. In large part because of the wind direction that day (note the direction of the flames in the picture below) spotting wasn’t nearly as much of a worry on our flank as it was the first day.
Like the first burn at MMR we participated in, the prescription for this day allowed for full-stand replacement. We kept the pace of the advancing flame front moving slowly in an effort to keep things “cool,” but some torching still occurred. Again, this really wasn’t a concern, just something for us to be aware of all day.
That just about covers the two MMR burns, unfortunately it was around this time that the camera on my phone decided it had had enough life and quit on me. I’m still hoping (somewhat unrealistically) that I can save the pictures I’d already taken, but I haven’t actually “tried” to extricate them from the apparently broken SD card yet. I’ll figure that out “eventually.” Probably.
Next I’ll be covering our year-end (ish) trip to Baker Island in Acadia National Park.
By far the biggest burns we participated in this past year were a pair carried out on the Massachusetts Military Reservation (MMR). A base that now goes by at least three names depending on who you talk to about it. Over two full days the prescribed burns on the MMR burned ~330 acres, both days we had highly active fire behavior, culminating with flame lengths somewhere around 100 feet high and a smoke column that (apparently) was visible from across the bay in Provincetown (35-40 miles). This entry is going to focus on the first of the two Rx Burns.
During the first of the two burns we were primarily a holding group, our job was to watch one flank of the burn unit and ensure that burning embers in the smoke didn’t light spot fires outside of the unit. What we were able to do if and when those embers did cross the line depended heavily on what the fuel type behind us consisted of. When we had our backs to a large grassy field, we were generally able to stomp out the fires before they grew much larger than a campfire. When we had thick brush or trees to our backs we instead called out for help and focused on staying out of the way of the brush-breakers as they barreled through the underbrush to put out the spot.
Luckily for us, the smoke was mostly heading in the other direction, which meant that for a large portion of the day we really didn’t have much to do except watch the fire work its way through the burn unit.
Fire behavior on the first burn was largely mild to moderate. There were a few instances of multi-tree torching, but complete stand replacement (when all of the trees in a clump burn and die in the same event) was within the bounds of the burn’s prescription. There are decent ecological reasons for allowing stand replacement, and since this burn was at least partially “for the bunnies,” the burn bosses were happy to let stands that were well within the perimeter ignite.
This first burn covered around 100 acres, a bit over half of what we’d hoped to do that day, shifting winds and caution kept us from hitting our mark. Day two, which occurred a few weeks later, would more than make up for the day’s potential shortfalls, though. I’ll get to that story next.
More pictures. This set comes from our first “larger” prescribed burn, carried out at Pilgrim Heights in Truro.
We were blessed with good, consistent weather all Spring. It was cool and dry, and over the course of the last few months we managed to get in over thirty (30) days of prescribed burning. I’m not exactly sure, but I think that the actual number is getting close to forty at this point.
Much like the pile burning over the winter, the mechanics of broadcast burning quickly became business as usual. Our standard operating procedure relied heavily on setting up looping hose-lays around the burn area before even lighting a test fire. While this strategy takes a little while to set up, it also greatly increases the safety of the whole operation. And in the long run I’m sure it made our lives a great deal easier.
To set up those crucial loops we used inch-and-a-half hose as our trunk line and every 100 feet we split off a 50 foot length of 3/4 inch hose. Optimally, that meant that we had complete coverage of the burn perimeter. In actual practice that wasn’t always true, but adding more 3/4 inch hose to the end of existing lines was a trivial fix to a generally non-pressing problem.
After the hose lay was in place we’d light a test fire and hold a briefing while watching it burn. Running the test fire simultaneously with the briefing is (apparently) somewhat atypical, but it did give us the advantage of being able to directly observe what the fire-behavior was likely to be before we began proper ignitions. It also sped up the day by getting two crucial steps in the burn process over with at once.
Test fire completed we’d go about the actual burn — using drip torches to lay down lines of fire, then using the 3/4 inch hose to extinguish one “edge” of the thickening line. The other edge was allowed to (hopefully slowly) burn across the unit until until it hit another line of fire coming from the other direction and went out from lack of fuel to burn.
Once there was no more active flame in the unit we’d use the hose ringing the area to soak everything still smoking, spending extra time making sure that rotting logs and other areas where embers could be smoldering were well and truly saturated.
After the last smoking embers were drowned we’d break up the hose-lay, roll everything up, pull our warning signs off the sides of the road, and head home.
Almost every prescribed fire we lit all year followed that same basic formula. Therefore, I’m going to just skip describing most of them and move on to posting the pictures and talking about the few times when things were — for one reason or another — different.
For instance, all of the pictures in this update were taken at a burn we carried out at an old Boy-Scout camp. The Boy Scouts sold the campsites to the Cape Cod National Seashore a few years back and our burn was step two in preparing the site to be used as a special group campground in the future. We also spent the better part of a day dismantling most of the old camp’s decrepit structures.
This burn was a little bit different since there were already defined paths all around the burn unit. Those paths were free of fuel (needles and brush in this case) and provided a secure enough fire-line that we didn’t need to surround the burn area with a hose lay. Instead we carried in 5-gallon backpack pumps and used them to discourage the flames from crossing the paths.
Our fifth prescribed burn took place in the afternoon of the same day we conducted our fourth. Tactically, it was considerably more involved than the burn in the morning. Again, we split into two groups and walked the two flanks of the burn area laying down boxes of flame in tandem. However, this time we also lit point ignitions in the interior of the burn area. This strategy, coupled with our use of a backing fire throughout the burn, led to a much more complete burn than we achieved earlier in the day.
It was remarkable to me how efficient “drawing” the rectangles on the ground with the drip torch was at creating a solid black perimeter. Once the rectangle is drawn the heat from the flames causes the air in its center to rise quickly, air from outside the rectangle then blows in to fill the space. This constant inwards wind creates head-fires all around the rectangle. As I may have mentioned, head fires (fires in which the flames are bent over unburned fuels) burn faster (though less completely) than backing fires. Since the rectangle strategy creates a ring of head-fires, it creates the desired black perimeter faster than the alternative.
The alternative to the rectangle strategy is simply lighting a long line of fire using the drip torch. On the one hand you use less than half the fuel, but on the other it doesn’t burn nearly as quickly (nor, in my incredibly limited experience, so well).
Hopefully, now that Winter is gone (at least as far as the calendar is concerned) we’ll be able to do more of this, it beats the snot out of shoveling.
As I’ve waxed more than is probably necessary about in the past few posts, we’ve been in a bit of a work-rut lately. The truth of the matter is that wintertime is when burning piles makes the most sense and so we took advantage of the often snow-covered ground as much as we were able. Making and burning piles every day had a few notable advantages, it gave those of us who needed it (myself very much included) ample time to practice using and maintaining our chainsaws, it allowed us to stay warm while being fantastically productive during the cold winter months, and it made me pretty much impervious to the smell of own hair burning. Take that last one as you will.
At any rate, although there are plenty of great things about burning piles, it really just isn’t the same as helping with a proper prescribed burn, so when I found out that we’d be returning to that sort of job today I was thrilled.
After collecting everything we’d need for the day and donning an extra layer of protective gear (beyond what we wore every day this winter) We traveled to the Doane Rock area in Eastham to await our exact destination and final instructions. It turns out that the Cape Cod National seashore has more than a few burn plots already established in that area, and we weren’t sure exactly where we’d be working first.
Once we established our objective (and walked around the perimeter as a group) we split into two teams and began using drip torches to burn strips along the outer edge of the flanks, progressing around the burn area in tandem until we met again on the other side of the field. Each strip started out as a 2 by 10-20 foot rectangle placed in such a way that the fire was encouraged to burn inwards towards the center of the plot while leaving a solid line of nonflammable black ground in its wake.
As the strips burned inwards we extinguished the flames that edged out of the boundaries we’d established during our pre-burn perimeter walk. Eventually, the fronts progressing from each flank met each other in the center of the plot and (with all the fuel in the area consumed) petered out without much further interference from us. The whole process (from the perimeter walk to the last wisp of smoke) took a few hours, though it certainly felt shorter.
From here we moved on to a second burn, but I’ll save those pictures for later.
Each day is a little warmer than the last, and now that the clocks have sprung past Daylight Saving time yet again there’s actually a decent amount of light left after the workday is over. The flip side is that unfortunately, its back to being utterly black out when I wake up in the morning. Our service with the National Seashore has remained, unlike the light levels, pretty much static over the past few weeks. Most days are some variation on cutting trees, piling branches, and burning everything. I’ve completely lost my ability to smell wood smoke on my clothes, I’m guessing that’s because everything I own is saturated with it. Think I’m joking, take a look at what my schedule has been for the past month:
There are a few novel projects in there, sterilizing our house while a particularly nasty flu-variant was moving through the other Americorps members like wildfire was a change of pace, as was constructing the educational boards for next years S-212 class at the Seashore. Other than that though, its been all fuels management, and I have the pictures to prove it.
No doubt, as the weather warms our assignments will begin to vary a little more. On the plus side however, we’ve gotten a massive (from my perspective at least) amount accomplished in the last few months. Between the Americorps members and the Fire Crew members we put in 400 person-hours a week on projects like these. Things get done.
After spending the coldest part of the winter staying warm by cutting down the pine trees across the street from our house, we finally got to start enjoying the fruits of all that labor. For the past few weeks we’ve spent about half of our days burning all the piles we’d created since we started chainsaw training several months back.
As is normal for our days with the Cape Cod National Seashore, we start burn days with a briefing in which we go over the weather, a safety talk, and the days task. When the weather permits (and with all the snow on the ground we’ve been able to burn with relative impunity lately) we then proceed to collect the materials we need – Drip Torches, Rakes, Hoses, Leaf Blowers, Chainsaws, Road Signs, Fuel, ect and head to the project site.
The actual ignitions are facilitated initially with the liberal use of a drip torch and a leaf blower. However, once a pile has been reduced to embers we can stow the torches and substitute a bucketful of glowing coals to ignite new piles. The resulting bonfire is further stoked by constant application of air through the leaf-blowers, which keeps the pile burning at full blast until all the fuel is expended.
Unsurprisingly, the bonfires are extremely hot. Really, there’s a reason we wear fire-resistant clothing. Our facial hair was the first thing to take the heat poorly. Unfortunately, extravagant beards and open flame don’t mix. We’ve gotten much better at coming away from the workday not covered in soot, but we still have a long way to go before we’re capable of working this close to a roaring fire and not getting a bit crispy.
Our third prescribed burn this year was scheduled for October 18th. The goal was to burn a several acre cranberry bog at the behest of the owners of the Dry Swamp Bog organic farm in Orleans. They seemed to be of the opinion that burning the bog would clear out a variety of undesirable species that they didn’t want to control using herbicides while also reinvigorating the soil.
Never having done something like this before, and having a minimum of terrestrial farming experience, I was initially skeptical that we’d even be able to get the fire started (Bogs aren’t exactly on my top 10 list for ‘most flammable places’). On the other hand, I’m all in favor of reducing herbicide use (especially in wetlands areas) when possible, and was completely willing to give them the benefit of the doubt.
At any rate, after loading three trucks and a fire engine with all the gear we’d need to light a bog on fire, we set out and arrived on the property before noon. The first thing we noticed (as we should have) was that the entire bog area sat only a few inches above the waterline.
Ok, that shouldn’t have been a surprise. The area we were to burn was surrounded on three of four sides with trenches that were full of water. Those trenches formed natural control line, although as we found out, they weren’t perfect.
Sizing up the property our boss found one place in particular, a corner where there were nearby structures, that deserved extra protection and parked out one fire engine there on the off chance a few unlucky firebrands crossed water filled trenches.
Due to the nature of the cranberry bog: the wet, the shade covering half of it, the sparse/low vegetation. We were to use fusees (effectively longer lasting road flares used to ignite material by hand) and a handheld torch fueled by a backpack mounted propane canister We also had four backpack pumps that we were to use for control and mop-up after the burn.
As we’d feared/expected, the bog didn’t burn particularly well. The bearers of the two torches walked back and forth across the burn area using the long-handled flamethrowers to place dots of flame every 10 feet or so, creating a tight grid of small burning patches. The rest of us helped fill in the remaining space by using the fusees to light particularly promising patches of dried plants and by physically moving flaming material into green (unburned) territory.
The only snag came when, as the burn boss had predicted, a few firebrands made the jump across the trench near the lone structure adjacent to the bog. There they burned merrily for nearly a minute before they were drowned by a fast acting firefighter standing by the engine’s internal pump. I wish I’d been nearby to get pictures of that sequence of events, but I was busy carrying burning grass around on the other side of the bog at the time and only heard about it over the radio.
Mop up was minimal after such a low intensity blaze, but we still spent the better part of half an hour at the end of the day extinguishing every last whisper of smoke that had been rising from the field.
As I mentioned above, the only fuels in the burn area that consistently ignited were the tall brown stalks. The cranberry plants themselves were pretty much immune to the attentions of the propane torches. While this made for a somewhat low-key experience from my perspective, I can’t help but think that the end result of the prescribed burn was fairly close to what the farmers that had asked for our help had hoped would happen. It will be interesting to see how this property recovers in the spring.
Despite this past fall being uncommonly wet (though far from dreary), we did manage to help with a few prescribed burns on the Cape Cod National Seashore. The first, our training burn, took place on a set of research plots one of our managers has been maintaining since the late 80’s.
Plots in this area are either burned or mowed at different intervals. We were starting burns on two of the shorter interval burn plots. Both were small burns, as these things go, neither more than 1/10th of an acre. Even so, our boss from the Seashore kept us in full firefighting kit the entire time.
For this small burn we started by making a scratch line — a thin strip without potential fuel in it — around the edges of the burn area using rakes. Then half of us crossed back and forth within the burn area using drip torches to light parallel lines of fire on the forest floor while the other half patrolled the scratch line with backpack pumps dowsing the flames as they reached the edge.
Drip torches (the metal canisters on the ground in the picture above) are carried at arms length and lay down a line of burning gasoline and diesel fuel. On this particular burn, having a consistent source of ignition was useful, both because of our inexperience and because the dappled shade and low fuel load at the site made it more likely that we wouldn’t be able to get a complete burn on the plot.
The affect of sunlight on fire was something I was under-aware of prior to coming to Cape Cod. The effect was particularly noticeable on this burn, where burning fuel in the shade simply wouldn’t spread as far as that which was spilled in the sun.
Because these plots had been burned so frequently, every other year in fact, there wasn’t much fuel on the ground. The flames from the fires we started here never grew to be more than about a foot. We mopped up using backpack pumps, making sure that there wasn’t so much as a whisper of smoke still emanating from the ground before we packed in for the day.