W.T.Manning Gabbro Quarry

Mr. W. T. Manning operated the Gabbro quarries for which the old PBR Pratt bridge crossing the Middle Patuxent River was called because of its close proximity to the Gabbro rail siding station.  The impressive remains of the stone crusher and elevator, larger than those for the nearby B.F. Pope Stone quarry which also provided hardrock for building roads, are clearly seen along the Wincopin Green Trail (see map and photos).   The larger of the Manning gabbro quarries is on the other side of the ridge towards the Middle Patuxent River, and it appears there was a terraced descending pathway/trail either for use by a small railway (an old rail was found near the top of the hill) or for carts to bring the quarried stones down to the crusher and elevator.

Gabbro is a very hard intrusive igneous rock like granite but differs in how it is formed, mined, and basic chemistry.  Both are great sources of crushed stone for road building but granite is more suited for monuments and building stones due to their lighter color, texture, and formation.  The quarries in the Guilford area towards Atholton mined granite, while those in the Savage area all mined gabbro.  The Manning quarry railroad siding was just over 2,000 feet downstream from the B. F. Pope quarry rail stop and 1,000 feet from the Pratt Bridge over the Middle Patuxent River.

William T. Manning was also a very interesting person.   Mr. Manning was the chief engineer of the Baltimore and Ohio Railroad at the early age of 37 and he held patents on rail car engineering.  He was a consulting engineer for the B&O and other railroad companies after he retired in 1899.   He lived in the Guilford 6th Election District according to the 1910 census where he started his gabbro quarry and stone crushing business along the Little Patuxent River in the area known as Wincopin Neck.   Mr. Manning died of heart troubles at the age of 62 in 1918.