Building bridges with the community – Part I: when DIY portable bridge deck kits are not enough (September 2014)

[This post is being published out of order; the story is from September 2014]

Disclaimer: This post does not contain any technical information or advice for constructing or repairing bridges that are safe and structurally sound. Do not use anything written below as a guide for bridge construction or repair.


We left Grimari in two MSF Land Cruisers in the early morning of the first of September’s four Thursdays, intending to drive 60km south to Lihoto. Our objective was simple enough: ask a few questions, have a look around the town, make some basic observations on people’s living conditions and, hopefully, draw some initial conclusions about possible unmet healthcare needs. This evaluation would inform our decision to do something or nothing in Lihoto.

It was thus that we trundled forward through the morning fog as it lifted gently off the tall grass that leaned out over the dirt road. The broad green blades slapped the windshield in front of me while my window – open just a crack – harvested leaves, twigs, and angry little black ants that only bit me once they’d found someplace difficult to reach. Pulling my trousers down while in a moving vehicle to crush the ants in my pants would have been technically challenging and a tad unprofessional, so I set to work pounding my thighs and shins with closed fists as if I were playing whack-a-mole at a funfair. I didn’t win any prizes, though.

With the ants defeated, the windows shut for self-defence, and the air conditioning moderating the greenhouse effect of all that glass, I set my mind to enjoying the surge of caffeinated optimism that often washes over me during early-morning trips to new and exciting places. This warm feeling didn’t last for long.

My wristwatch GPS unit showed a paltry 6.0km travelled when we stopped and climbed out to assess the first of several bridges to cross that day, the Pont (bridge) Boungou. I had sent a motorcycle driver the day before to check the road conditions all the way to Lihoto, and he had assured me that the Pont Boungou was easily crossed. We would only need to strap some wooden planks to the vehicle roofs and lay the planks down across the existing metal beams to create a bridge deck. We faced this situation frequently, and had planned accordingly.

Unfortunately, having arrived on the spot, we discovered the motorcyclist had judged the bridge structure rather poorly. Three of the original I-beams remained but they were each twelve metres in length, far longer than we could cover with our homemade sixteen-plank portable bridge deck kit. A deviation through the slow green water to the east of the bridge seemed to be the only plausible alternative, but recent rains had raised the river level to roughly a metre above the riverbed. We couldn’t risk destroying an engine, so we spun the Land Cruisers around and headed back toward Grimari. To avoid wasting the day, we quickly put together a backup plan: we returned to Grimari then headed north-northeast to explore the communities along the road to Bakala. We succeeded to reach a village called Takobanda, farther than we expected to reach, given the fact that we’d lost a full two hours on the aborted trip. All through that day, however, I couldn’t get the bridge out of my head. As we crossed multiple bridges, repeating our time-tested plank method, I kept imagining how we might use that experience to rehabilitate the Pont Boungou.

Before I continue, let me explain, with photos, how we cross bridges that are not otherwise passable. First, we buy wooden planks and cut them into 3-metre lengths. 3m is long enough to lie crosswise on the metal beams typical of the small bridges found throughout the area, and this length also allows us to safely strap the planks onto the Land Cruiser roof racks.

Preparing wooden planks in Grimari, for the portable bridge deck kit

Arriving at a bridge in disrepair, we assess the strength of the existing metal beams and any wooden decking that remains. We then offload the planks from the roof, arrange as many as needed crosswise to create a decent bridge deck and, lastly, we place a few planks as lengthwise runners for the vehicle wheels. This last step is very important, to distribute the load across a greater surface area on the bridge deck.

This is what it looks like for a short, 3.3-metre long bridge:

3.3 metre bridge with portable bridge deck kit in place
MSF Land Cruiser crossing 3.3 metre bridge

Right after the successful crossing, we reclaim our lumber and load it back onto the Land Cruisers:

Cyrille and Mark removing our portable bridge deck planks
Loading the planks back onto the roof of the MSF Land Cruiser
Loading the planks back onto the roof of the MSF Land Cruiser

As the day went on, I began hatching a plan to restore the Pont Boungou to working order so that we could reach Lihoto the following Thursday. Over the weekend I found people willing to work for about five dollars a day, and by Monday morning a dozen young men from the nearby village of Ngoulinga were clearing brush at both ends of the bridge. My assistant, Papa Zach, and I arrived on the spot at 06:42 that day. We were immediately impressed by the team’s early morning enthusiasm and the visible progress.

Tall grass cleared by daily workers at the north end of Pont Boungou, outside Grimari, Central African Republic
Backer makes notes at the north end of Pont Boungou

While standing with Papa Zach on the steel beams over the water, my thumb and index finger stroked the hair from the edges of my mouth down to my chin, over and over. It was during this period of pondering that something among the reeds on the other side of the riverbed deviation caught my drifting eyes: the tip of the fourth and until-now-missing steel I-beam was poking out at such an angle that it could only be seen from the middle of the bridge.

Uncovering the missing bridge beam

Zach and I agreed before we’d even discussed – we would try and reinstall the old metal beam before building the wooden bridge deck.

We appointed a gentleman named Backer as the site supervisor to coordinate the work in our absence. Older than any member of the group by at least a decade if not two, Backer used to be the radio operator for the Grimari aerodrome, a laterite landing strip unvisited by aircraft in over twenty years. We agreed on the following steps to achieve our objective:

  1. Pull the metal beam from the mud and assess its usability;
  2. Cut 40 trees as straight as could be found, 4m long and approximately 20cm in diameter, and transport them to the worksite;
  3. Install the fourth metal beam, if possible;
  4. Attach wood to beams using vines, and strengthen by nailing joints together;
  5. Test drive, hopefully without falling in.

11 men heaving at an incredibly heavy bridge beam
The men discuss their strategy before continuing to move the bridge beam

By the end of the first day, the metal I-beam was up at road level, a few metres shy of the north end of the bridge. Severely bent and a bit twisted from the accident that destroyed the bridge, we found no signs of corrosion on the beam, and decided to use it as an additional support. Across the water, we had ten small, not particularly straight, tree trunks lying at the side of the road. We’d also succeeded to locate eight solid timbers at a nearby college, each 8cm x 23cm and 6m long, which had long ago been intended for rebuilding the bridge deck. Since political instability put those plans on hold, the timbers had been sitting patiently in the grass, accommodating all manner of ant, termite, and woodborer species, waiting to be put to good use.

On day two, the team chiselled and smashed and dug and clawed until a slot on each side was ready to receive the metal beam. While this work was beginning, two men were busy sawing the timbers into three-metre lengths, which we picked up in the Land Cruiser and drove to the worksite.

Sawing thick timbers for bridge supports
Timbers loaded into the Land Cruiser

The main group soon set off in search of additional small trees to place crosswise onto the beams, and strong jungle vines to lash everything together.

Two men carry a log for bridge repair near Grimari, Central African Republic

By the end of the second day we’d successfully moved the twisted metal beam to within a metre of its intended position.

11 men slide the bridge beam gradually into place
Two men carry a log for bridge repair near Grimari, Central African Republic

The third morning saw the guys place the twisted beam exactly where I wanted it.

During the final big heave, one of the daily workers let his attention slip for a fraction of a second and was rewarded with a deep gash halfway through the last segment of his ring finger. I immediately cleaned the wound, did a quick dressing with sterile compresses to stop the bleeding and wrapped it with a gauze bandage to hold the two flaps of finger flesh flush with each other. With the compresses securely held in place by the first half of the steadily unrolling bandage, I brought his pinkie finger up against his ring finger and wound the remainder of the bandage around the pair, thereby immobilising the injured digit. We then drove him directly to Grimari for proper medical care.

In the afternoon, we returned to the worksite and found a sturdy-looking bridge had appeared!

Timbers and logs lashed onto metal bridge beams at Pont Bongou, Central African Republic
Lashing the bridge deck onto the beams

Following a visual inspection, we tested the structure by driving the Land Cruiser across.

Seeing as how we arrived intact on the other side, we judged the job a success. A few improvements for long term durability, such as planks for the wheels to roll along, would be added later on.

Early the next morning, Thursday 11 September, we began our second abortive attempt to access Lihoto. This time we crossed the Pont Boungou without difficulty, but what we failed to foresee was the floodwater farther along the road, which, at the forty-kilometre mark, would ultimately force us to turn back.

The motorcycle driver who had earlier assured us that we could drive across the Pont Boungou, also promised that we could easily drive through the shallow water to the west of the Pont Pende. Pulling up to the crossing, however, our hope of reaching Lihoto quickly faded. We spoke with some locals hanging around the area, and one gentleman agreed to wade into the “shallow” water to give us an idea of the depth:

A man shows the depth of water at the location of the nonexistent Pont Pende

In the time it took us to decide that we could not safely make it to the other side with the Land Cruisers (the water was two metres deep!), I had a good look around and came to the conclusion that we could easily build a new log bridge with enough men from the local villages. And so it was that we hatched our second bridge building scheme in as many weeks.

To be continued…

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