MICHIGAN ROADS AND FORESTS 



HIGHWAY BRIDGES AND CULVERTS, fund would make a welcome addition to the stone in most localities prohibits the use of 



(By John J. Cox, Sturgis, Mich.) fun(ls available for road purposes. masonry. We then: have left for consideration 



Since the beginning of the present National ' n considering the classes or kinds of construe- two kinds of construction, namely, steel and 



movement for eood roads there has been a vast tion> and for convenience in the same, I will concrete, or reinforced concrete. Careful 



n a vast make a distinction betw een bridges and culverts, study and actual experience with conditions 



leant of discussion and investigation of the i w ;n ca ii all spans of six feet and less culverts, has shown that all bridges of fifty feet or 



various elements entering into the work of pro- all above six feet, bridges. My reason for so 'ess should be constructed of concrete or rein- 



viding good roads for country districts Good doing is, that the construction of greater length forced concrete, as this is the most permanent 



bridges are a very essential feature of good tha " s ' x *<j et inv lve P rinci P, les , of b " d 8? desi S n f rm of construction known to engineers to- 



and should not be attmpted by those inexper- day. The cost of building these permanent 



has been made of them i en ced and without some knowledge of this sub- structures for such spans is reasonable and 



in the past when good roads were under discus- ject. Some engineers may obpect to this classifi- oftentimes they can be built for the same 



sion. This could scarcely have occurred from cation on the grounds of its being misleading, price or but very little more than steel struc- 



their lack of importance if importance is to be but f r . the P ur P se of this P a P er - the distinction tures with concrete floor, designed for the 



measured by cost as bridges are an item of very ls sufficlent - same loading. 



considerable cost both singly and in aggregate. The subject of culvert construction is largely The advantages of concrete over steel 



In the eighty-three counties in the State of one of local conditions and materials. Culverts bridges are as follows: Concrete bridges are 



Michigan in the year 1907, the cost of bridges and are built of wood, vitrified clay pipe, metal, permanent improvements and need neither 



culverts in Branch County alone that same year masonry and concrete and in the form of boxes, painting nor repairs; they are flood-proof, 



amounted to $13.525. In St. Joseph County, pipes, arches and sewer shapes. Considering the frost-proof, rust-proof and fire-proof, and 



$8,306; and this is not an exceptional year but cost an d maintenance wood culverts are the have no wooden floors that are periodically 



rather one of minimum expenditure. Let us most expensive culverts built. Following wood out of repair. With the advent >of good roads 



look at the year following the year of 1908. closely and almost as high is the corrugated the traffic on our highways grows heavier, 



Branch County raised $20.808 for road repair and metal culvert. Aside from being high of cost steel and wooden bridges grow weaker, con- 



$21,843 for highway improvement, making a both in price and maintenance in many cases crete bridges grow stronger. Concrete 



total of $42,650 as a highway fund. Out of this the y ar e dangerous. They are made in sizes from bridges are largely built with home labor and 



amount $24.032 was expended on bridges and twelve to sixty inches and their use is not recom- materials. To build a concrete bridge, then 



culverts. This is more than 56% of the entire mended. Cast iron comes next in cost and gives the money expended returns directly to the 



highway fund. St. Joseph County raised $10,356 varying results, depending upon the style used, taxpayer, while in steel construction very 



for highway repair and $25,660 for highway im- Cast iron pipe from twelve to forty-eight inches little home labor and materials are used. 



provement making a total of $36.015 as a high- makes a very durable culvert. It is not easily Let us take for example a supposed case 



way fund. $13,753 was expended on bridges and broken and is put in place without much difficulty. one that is identica i to cases OCC u rr in g in our 



culverts or more than 38% of the entire highway Vitrified clay pipe from 12 to 36 inches makes townships and cities eve Suppose a 



fund. Neither of these are uncommon expendi- excellent culverts if used in suitable locations tow n s hip wishes to build a bridge of say 



tures as most counties spend a large part of their and properly laid They should not be used forty _ f , oot span . This township f as a ' od 



road money for building and maintaining bridges where water will stand in them as it will freeze credit with no indebtedness, bl f t js usin * Jg 



and culverts. The reason for this is that a large and crack the pipe, nor should they be used near it income f curren t exnenses Thp town- 



proportion of existing bridges as well as many the surface of the road where the wheels will ship bZo w^ from bank II 000 and h^vs" 



of those now being built are only temporary cut them. Next comes our masonry culvert, i , brid ith wooden a ' , 



structures. The fact that our present bridge ex- built of. rock. Those built of stratified rock are * ee Q \ ^yeaTs thfs bridge refloored 



penditure is largely one of maintenance is respon- very satisfactory and especially so up to spans of , f jjL * ]00 f P , rfl r i: l2. At 



sible for this condition of affairs. 5 feet, but those built in this part of the state R,tSJih of foSr vear, th P hr 



I cannot explain the limited amount of consid- from our Michigan cobble stone are only tern- ^"'^ cost of $50 for each" nfiU "NO ? 



eration given to the subject of bridges unless it porary structures, with varying degrees of satis- ?h e en^of tw!n y -five yeL ? ofte of Jain t 



is the lack of far-sightedness and of economic faction. The best material to build culverts of P* and " renewals the *?? *' 



training along these lines of our communities. is concrete, and in counties, like Branch and St. "^ a J I^Th?" JSSrSf^ >h *" '* 



" " On a 6 per cen? basis The inte^ 



$1000 borrowed at thp hant if 

 tooSS^J? inH th 1 nnn 



a ,M Of 

 "? u "P ad : Of , course a conserva- 



properly applied to the roads. There is a right- sure the subject needs a little forethought con- .bSkfa* i^S?v pr b ?, bly " Ot b rrow at 



ful demand for expert supervision of public nected with a small amount of working knowl- * he b a "-J but ."""" e money is worth 



schools by licensed instructors, but the roads edge of cement and a good allowance of good 



which are of next importance and upon which common sense. A better plan still would be to 



anng aong ese nes o our communtes. , , . 



State" Highway Engineer of Missouri, Curtis Joseph, where there is an abundant supply of 



Hill, said in one of his bulletins; "People are in- gravel and often times right on the site, ready 



appreciative in so far as they are indifferent for use, why should we use anything else? How 



about how their road funds are expended, never cheaply and easily these concrete culverts can be 



seeming to realize that monev is lost if not built is only realized after building them. To be 



. 



" * 



h-s nH for h fi , * \ 



P firSt twent y- five 



wc are o nex mporance an upon wc common sense. ee ! , 



there is the next largest expenditure, must take standardize these culverts in sizes as much as f" 



care of themselves. Men as a whole are about possible and then limit the number of standard i, nt fl e " $ 60 per year. ... $1, 



possible and then limit the number of standard , fl per year. ... 1,500 



dia- * ^ , nve y ears ( f ur t! mes ) 4 



as well fitted to teach school as to make roads, sizes. No culvert should have a width or a- 



To take the expert supervision away from the meter of less than one foot and larger sizes * epa ''"f 



schools and let everybody try to do the teaching should be expressed in even feet without frac- ; tal ? 



would be about as "sensible as to let everybody tional arts. After this, have a set of standard an 



try to make roads. A business would soon be- 



, 



fou f .>? ars (four tlme l) 25 

 ' hlch . amounts to $86 per 



would be about as "sensible as to let everybody tional parts. After this, have a set of standard f e ' 000 , originally borrowed, still 



try to make roads. A business would soon be- plans and specifications drawn and whenever a ] l" P -', m . ust , now be '""eased to $2,000 or 

 come bankrupt if run in the same manner as the culvert is needed in your township build it ( l , a br ' d se. The township now bor- 



v , 



mad business in some communities." according to these plans and specifications. By ws another $1,000 and builds a new bridge 



An authority on road making has said of so doing in a short time you will find yourself nd > and for the next twenty- 



American ways : "Men are taken from their a long way on the road toward permanent cul- st P av ln . tere , st on f 2 ' 000 > amount- 



peculiar occupations in which they are skilled and verts. ^V. 3 year ' *t the end of fifty years 



transferred to others of which they know noth- Bridges are classified along several different * 



ing. A good plowman does not think himself lines, such as according to use, according to ma- 



competent to forge the coulter of his plow, or to terials used in construction, and according to the 



put together the woodwork. He knows it is form o f structure. In fact the classes are so deht 



truer economy for him to pay a mechanic for his numerous that it is beyond the scope of this paper " 



services. But the laws assume him to be a skill- to ta ke up and discuss each and every class of t 



the nd of < 



*f,i u" ' f ,:5 ^"^ ?? /fl, nnn 

 n ^ " lft ' 95 ? + \ nd b ,^ $3 ' 



f b ildfn n h i , for T e t ' * he ' old P r b " 

 * ' " B " !t takes no nnan 



f + 

 building , of temporary steel 



to bankruptcy or higher 



t 



ful road-maker-a more difficult art than plow- bridge . The bridge we are looking for and the brides 



making, and compel him to act as one though his one under discussin, is the economical bridge. 



clumsiness in repairing his plow would only in- The most economical bridge is that one which in c,. ' sp : A - . 



lure himself, while his road making blunders are the long run will give the best service and cost i? P ^ r , t a permanent concrete 



injurious to the whole community." the least money . The first cost of a bridge is tha the fir.t ^.t 1 f^ ! ?t~ty TA 



This same thing is true both of the past and not a safe criterion upon which to base economy. cost , of the s . te ^ bndge, 



the present in bridge building and to solve this Much money is wasted in cheap, flimsy bridges on T '"i 1 ' " rep t ? mn . B and , . no r epamtmg. The 



problem in bridge economics we must get down wbich are sho rt lived, unsatisfactory, and con- for i, ; . t , Own ' hlp w ." ld , have been 



to the fundamental principals that are involved tinually in need of repairs. The possible life !i3 3 <, iuf5 paid . and an indebtedness of 



in this expenditure and in the remedy. of any brid ge is difficult to estimate. Steel ' } ^ r V ld never need to be ">- 



The majority of our bridges are spans of 50 bridges, if properly constructed should last from Th' 



feet and less, yet the largest portion of the 25 to 40 yea rs; combination bridges from 12 to ordin^rv hr T T I Procedure at the 



bridge money is spent in renewing these short i vears- timber hridfes from in tn i* vf-arc- cu . nar y bridge letting has a marked tendency 



It s evident then that the annual ex- if, " ^so^and^eTn^ed concrete' b'ridTes S.eTommo^ mTho^' f f ^^ brldgeS 



common m 



brides .eommo mho f 

 penditures for bridges might eventually be very are permanent structures C common method of awarding contracts 



materially reduced by adopting the policy of with the present oricp of timber ind its i u"r a , S follows: Thr ee or four 





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