thus it may be seen that the total load bearing capacity is significantly increased by utilising the lower beam portion 20 and integrating it with the bridge structure comprising upper beam portion 28 the member initially making the span is not wasted and becomes an important part of the overall structure unlike prior art bridges of the general type decking 56 is placed on and connected to the top of upper beam portion 28 this may be done after the upper beam portion and lower beam portion are connected together however preferably the decking is placed and connected to individual beam members 30 and 32 prior to transport of these members to the job site this is illustrated in fig2 the amount of work and assembly that must be done at the site of creek 18 or other bridge location is consequently minimized fig8 shows an alternative method of moving the lower beam portion 20 across the ravine or such gap to be spanned the beam portion 20 is supported on a roller 70 cables 72 and 74 are connected to opposite ends of the beam portion the beam portion is to be moved to the left from the side of the gap where the roller is positioned this is accomplished by pulling on cable 74 with for example a tractor a truck or a winch a winch adjacent the roller may be used by looping the cable 74 about a pulley connected to a fixed object on the opposite side of the gap arrow 76 denotes the direction of the pulling force on cable 74 and the direction of movement of the beam portion back tension is maintained on cable 72 as indicated by arrow 78 to keep the beam portion 20.