New-York tribune., 1908-05-20
PROF. BURR CALLED In
TO STUDY BRIDGE WORK.
Commissioner Stevenson TO Ge1
ReD0rt on Blach7ceHs Structure.

| After ten days of grim, immutable silence re
! garding the mass of evidence pupiisheu III in
| Tribune pointing out the danger that ,he pia.
wells Island Bridge is being overloaded the bFios
! Depar rtment has last moved. even il II mas ho
| spoken.
Controller Metz is authority for the statement
| that Professor william II. Burr. of Columbia oni
versity has been asked by Bridge 1oh'iiSsiohe'
| Stevenson go the strains ana s'fesses VI
| the new bridge 1t is evident that the Coinmis-
s,oper s mt so sure OF his position ne was some
davs sro when he declared that his departments
| engineers perfectly sure that the plIuse ""a
absolutely safe and called fears absurd FEoiessot
Burr is ALREADY employed by the Bridge Depart
ment in an advisory capacity in connection with
the work upon the new Henry Hudson Bridge and
will doubtless be able to assist Chief Engineer
Ingersoll. who 10 not bridge engineer IN coming
to a decision as to whether 1t is wise to nave
complete and thorough examination or the ne"
structure made by commission Of impartial engi-
neers not in any way connected with the depart
ment.
Chandler Wilmington. chief engineer of the
Finance Department. who was instructed by Con-
troller Metz previous to the meeting OF the Board
OF Estimate and Apportonment Friday to in
quire the statements that the Blackwels Island
Bridge being dangerously overloaded, has not
yet made his report. and the Controller says he
has idea what recommendations the report will
contain.
Borough President Coler unsuccessfuly endea-
vored to have the Board of Estimate at fits last
meeting pass resolution naming the Borough
Presidents of Manhattan and Queens committee
TO report upon the naming OF expert engineers
not connected with the Bridge Department to con-
duct investigation. The resolution was not con-
stdered because the Mayor objected the ground
that no notice had been given of Mr.. Colers inten-
ton to introduce it. At the next meeting Borough
President Coler will introduce another resolution
upon the subject of which due notice has already
been given.
Controller Metz when yesterday afternoon
said: mo report has yet been made to me by Mr.
Wilmington regarding the BlaclwelTs Island Bridge,
although have had several talks upon the sub
ject. have also discussed the matter with Bridge
Commissioner Stevenson, and ] understand that
Professor William H Burr. OF Columbia College, has
been asked to make investigation to the safety
of the bridge In fact. several tests have already
been made. I expect that report will be made TO
the bridge department in a short time, but until
that report is made it is not likely that anything
further will be done"
Bridge Commissioner Stevenson in his last state
ment regarding the Backwells Island Bridge said
it would be foolish to waste the city's MAX
ing the tests of models of main compression mem
bers, because he certain the bridge abso-
lutely safe. He explained that Chief Engineer In
gersoll. John B. wilkins. Henry b. Seaman and
Leon S. Mosseiff. of the engineering staff of the
Bridge Department, had examined the wrecked
bridge at Quebec and had subsequently made
thorough and complete re-eXamination OF the
Island structure and had reported to
him verbally that the bridge was absolutely safe.
This statement was promptly challenged by Henry
B. Seaman, who clearly ntimated that he had
given the Commissioner such assurance. 1t
has been remarked by engineers outside the Bridge
Department that Mr.. Seaman, while member Of
the engineering staff of the Bridge Department.
was regarded the bridge expert. and that his
denial of the assertion that he reported the bridge
10 be safe after the re-examnation shows the
weakness of the position taken by the Commits
siOner This weakness is aCcentuated by the
ders issued that emplOye of the department
shall discuss the subject. --.-
Il Is most unusual. engineers assert for such a
report Commissioner Stevenson says he received
upon the re-examinaton of the Blackwes Island
Bridge TO be made verbally and is equally strange
that such a report should be regarded confden
tial Had the report in question been written one
there would be question Of veracity between
the Commissioner and Mr.. Seaman, and the publica-
ton of such a report would go long way toward
reas ssurfng the public that there danger OF
the bridge coming grief. But when Mr.. Steven |
sons own witness and of all his witnesses the one
qualified by experience and training to testify
ntrnates that he does believe that the Black
wells Island Bridge is absolutely safe. there is
little in the statement made by the Commissioner OF
Bridges reassure the public.
Now that Professor Burr, Of Columbia College. |
has been added to the engineering staff of the |
Bridge Department in an advisory capacity II |
seems probable the Commissioner will recede from |
his former position and agree 10 InOEOuSn anu |
complete examination of the new bridge by |
commission of really impartial expert engineers |
not in any way connected with the department |
This much the public has a right to demand, not |
only because well known and experienced bridge |
engineers have expressed the opinion that the |
hridpe will he dangerously unsafe loaded the |
department has announced it will be loaded, but |
because contract for the superstructure itself
calls for tests of the main compression members |
that have never been made
hare of
the work of constructing the Quebec bridge to
check their calculations by actual tests of the |
carrying strength of the main compression mem
bers of the bridge that resulted in the disaster.
Commenting upon this oversight by the engineers
Of the Quebec bridge The Engineering Record"
N its issue of April Ii last. says:
There is no definite evidence to show that
either Mr. Theodore Cooper, consulting engineer.
any investigation to be made of the test data that
were available and when the comparative magni-
ude of the undertaking is remembered, It is diff
cult to explain their failure to check their concu
sions the Phoenix testing machine, which
always at their disposal
1t is also pointed that prior to the Quebec
disaster it had been the habit of bridge engineers
o depend too much upon calculations not proved
oy actual tests made during the course of con-
,truction. Clause No. 81 OF the contract speCica-
ions of the Backwells Island Bridge provides
or the making of such actual during the
curse Of construction. Under that clause exten-
i've tests were made by the Bridge Department |
ngineers of the main tension members of the |
tructure. Eye-bars Of every make and material |
we're tried and tested before the of nickel
teel eye-bars decided upon but test
made of the main compression members. Yet |
was the failure of the main compression men, |
ers in the Quebec bridge which caused its col |
apse. The tension members strange say, with
TODD the tremendous strain OF the bridge falling.
nd only one of them broke under such abnormal
train.
If the engineers Of the Quebec bridge were Sc
erely criticised for their failure to make actual