Chapter 34

BRIDGE BUILDING.

Willow Clump Island was, for the most part, a trackless wilderness, and as soon as we had made our map we laid out roads to the different important points. Our main highway ran from Point Lookout to Tiger's Tail. This road was made rather winding, to add to its picturesqueness, and from it a number of shorter roads branched off.

SPAR BRIDGE.

We ran a bridge across the mill-race at its narrowest point. This bridge was made of trees which we had cut down in making our road. It was quite a piece of engineering, built under Uncle Ed's guidance. Two frames were made of the shape shown in Figs. 91 and 92. The side sticks were 15 feet long and spaced about 10 feet apart at the base by crosspieces. At the upper end one frame was made 6 feet wide and the other 5 feet wide. The side and cross spars were mortised together and secured by lashing a rope around them. To make the frames more rigid we braced them with diagonal braces nailed on. When completed we set the frames up on opposite sides of the stream and with ropes carefully lowered their upper ends until they interlocked, the side spars of each frame resting on the cross spars of the other. In the angles formed by the crossing side spars a center spar was laid, and a number of floor beams or spars were stretched to this from the opposite shores. On these a flooring was spread made of saplings, cut and trimmed to the right size. A rustic railing on each side of the bridge completed the structure.

THE ROPE RAILWAY.

The mill-race was crossed further down by a rope line on which we rigged a traveling carriage. A light manila rope was used, anchored to a tree at each side about fifteen feet from the ground. A pulley block with a wheel or sheave 4 inches in diameter was mounted to travel on the rope. Suspended from this block by means of fall and tackle was a swing seat. This, as shown in Fig. 94, was merely a board fastened with four rope strands to the ring of the tackle block. A single rope was used, with the ends tied firmly together. The loop thus formed was passed through the ring of the tackle block and the opposite ends were twisted over the ends of the seat board in the manner illustrated in Fig. 95. The tackle blocks were quite small, having 2-inch sheaves, and they, together with the large pulley or "traveling block," as we called it, cost us about $2.50. Two light ropes were fastened to the large traveling block, each rope long enough to reach across the stream. The ropes extended to opposite anchorages, where each was passed over a branch of the tree and belayed on a cleat within easy reach. A fellow could draw himself up clear of the ground by pulling on the free end of the fall, as a painter does; then tying the swing fast in this position, he would pull himself across the stream by means of the rope stretched to the opposite anchorage. The swing could be drawn back by the next one who wanted to cross. We also used this aerial line for transporting loads from one island to the other.

SUSPENSION BRIDGE.

Our aerial railway didn't last long. We soon tired of it, and instead utilized the materials for a rope suspension bridge. We procured from Lumberville half a dozen old barrels and used the staves as a flooring for the bridge. The staves were linked together by a pair of ropes at each end woven over and under, as indicated in the drawing Fig. 97. Notches were cut in the staves to hold the ropes from slipping off. The flexible flooring thus constructed was stretched across the river and secured to stakes driven firmly in the ground. A pair of parallel ropes were extended across the stream about three feet above the flooring, with which they were connected at intervals of five feet. The bridge was 25 feet long, and while rather shaky, owing to the fact that there were no braces to prevent it from swaying sidewise, still it was very strong and did excellent service.

PONTOON BRIDGE.

At the head of the mill-race, where the channel was fifty feet wide, we built a pontoon bridge. We were fortunate in securing six good cider barrels at low cost, also a quantity of "slabs" from one of the sawmills of Lumberville. "Slab" is the lumberman's name for the outside piece of a log which is sawn off in squaring up the sides. We made a raft of these materials and floated them down the river to Lake Placid. The bridge was made by anchoring the barrels in the channel about eight feet apart, and laying on them the floor beams, which supported a flooring of slabs. The floor beams were narrow planks 1 inch by 4 inches, taken from the bridge wreck, and they were placed on edge to prevent sagging. Of course we had no anchors for securing the barrels, but used instead large stones weighing about 100 pounds each, around which the anchor lines were fastened. We found it rather difficult to sink these improvised anchors at just the right places, for we were working at the very mouth of the mill-race, and were in constant danger of having our scow sucked down into the swirling channel. Once we were actually drawn into the mill-race and tore madly down the rushing stream. By Bill's careful steering we managed to avoid striking the shore, and just as we were off the Tiger's Tail Reddy succeeded in swinging a rope around an overhanging limb and bringing us to a sudden stop. A moment later we might have been dashed against the rocks in the rapids below and our boat smashed. Shooting rapids in a scow is a very different matter from riding through them on a plank.

THE KING ROD TRUSS.

Our bridge building operations were not entirely confined to the island. Two of them were built on the Schreiner grounds at Lamington. Reddy Schreiner's home was situated a little distance above the town where Cedar Brook came tumbling down a gorge in the hills and spread out into the Schreiners' ice pond. Thence it pursued its course very quietly through the low and somewhat swampy ground in the Schreiners' back yard. Over this brook Reddy was very anxious to build a bridge. Accordingly, before returning to school in the fall Bill made out a careful set of plans for the structure, and after we had gone the rest of the society, under Reddy's guidance, erected the bridge.

The structure was a cross between a suspension bridge and a spar bridge. The banks of the stream were so low that, instead of resting the floor of the bridge on top of the inclined frames, as we had done over the mill-race, it was suspended from the spars by means of wires. The crossing ends of the spars were nailed together and their lower ends were firmly planted about four feet apart in the banks of the brook. A stick nailed to the apex of each pair of spars served temporarily to brace them apart. The center cross beam of the bridge was now suspended from the spars by means of heavy galvanized iron wire (No. 14, I should say). The beam was hung high enough to allow for stretch of the wire, making the roadway incline upward from both sides to the center. Aside from carrying the floor of the bridge, this beam was used to brace the inclined spars when the temporary crosspiece was removed. The ends of the beam projected about thirty inches beyond the bridge at each side, and they supported braces which extended diagonally upward to the crossing ends of the spars. When this was done the temporary crosspiece above referred to was removed. As the span between the center cross beam and the banks was a little too long to provide a steady floor, a couple of intermediate cross beams were suspended from the inclined spars. The floor beams were then laid in place and covered with a flooring of slabs.

STIFFENING THE BRIDGE.

The bridge was a pretty good one, except for a slight unsteadiness between the center and either end. When Uncle Ed saw it he showed us at once where the trouble lay. Our intermediate cross beams were hung from the center of the spars, and consequently made them bend, because the strain came across their length, while at the center of the bridge there was no chance for the spars to bend, because the strain was exerted along their length, that is, it tended merely to push the ends of the spars deeper into the banks. To remedy the trouble he proposed propping up the center of each spar with a brace running from the center crosspiece. The dotted lines in Fig. 100 show how these braces were applied. They made the floor perfectly solid throughout, and gave the bridge a much better appearance. Uncle Ed told us that the structure might be called a "king rod truss," except that in place of rods we had used wires.

THE KING POST BRIDGE.

The other bridge on the Schreiner property was built in the following summer, just before we started on our second expedition to Willow Clump Island. It spanned the brook at the gorge, and was therefore a more difficult engineering feat. Mr. Schreiner himself asked us to build it, and we felt greatly honored by the request. A search was made in the Van Syckel library for a suitable type. At last we found one that seemed properly suited to the requirements. It was called a "king post truss," and was very similar to the king rod bridge. While the design of the bridge was simple, yet it required some ingenuity to put it together. In setting up the other bridge the scow had been anchored in the center of the stream and used as a working platform, from which it had been an easy matter to put the various parts together. In this case our scow was obviously of no use, so we laid a couple of long logs across the chasm, and a few slats were nailed across them to provide a temporary bridge or working platform. The platform sagged considerably at the center, because the span was fully eighteen feet; but the logs were large, and we knew they were strong enough to support our weight. However, as an extra precaution, we tied the ends to stakes driven in the ground, so that they could not possibly slip off the banks.

First we set about constructing the king posts, which were made as shown in Fig. 101. Two stout posts 7 feet long were connected at the top by a tie stick, which spaced them 4 feet apart. To make a secure fastening they were notched together and strengthened with diagonal braces. Each king post was notched on opposite sides, at about thirty inches from the top. A temporary tie piece was also nailed across the lower ends of the king posts. The frame thus formed was set up at the center of the span and temporarily held by nailing the lower tie piece to the working platform. Four stout spars were now cut, each about fifteen feet long. Taking a pair at a time, we planted their lower ends firmly in the opposite banks and sawed off their upper ends until they could just be hammered into the notches in the king post. This required careful fitting, but by making the spars a little too long to start with, and then shaving them down with a draw-knife, we managed to make fairly good joints. A couple of long wire nails in each spar made the structure perfectly secure. The king posts were now sawed off just above the temporary tie piece, and the permanent cross beam was fastened to these ends with straps of heavy wire wound tightly about them. The working platform sagged so much that we were able to lay this cross beam above it. From the ends of the cross beam diagonal braces extended to the king posts (Fig. 103). Our working platform was now removed and replaced with the permanent floor beams, which were firmly nailed to the center cross beam and to the inclined spars at the shore ends. The floor beams were quite heavy and needed no support between the king posts and shore. A rustic floor was made of small logs sawed in two at Mr. Schreiner's sawmill. Light poles were nailed to the flooring along each edge, giving a finish to the bridge. We also provided a rustic railing for the bridge of light poles nailed to the king posts and the diagonal spars.